/* gb.h - v0.01 - OpenGL Helper Library - public domain - no warranty implied; use at your own risk This is a single header file with a bunch of useful stuff for working with OpenGL =========================================================================== YOU MUST #define GBGL_IMPLEMENTATION in EXACTLY _one_ C or C++ file that includes this header, BEFORE the include like this: #define GBGL_IMPLEMENTATION #include "gb_gl.h" All other files should just #include "gb_gl.h" without #define NOTE This library REQUIRES "stb_image.h" for loading images from file - You may need change the path This library REQUIRES "gb.h" at this moment in time. This library REQUIRES "gb_math.h" at this moment in time. =========================================================================== Conventions used: gbglTypesAreLikeThis (None core types) gbgl_functions_and_variables_like_this Prefer // Comments Never use _t suffix for types (I think they are stupid...) Version History: 0.01 - Initial Version LICENSE This software is dual-licensed to the public domain and under the following license: you are granted a perpetual, irrevocable license to copy, modify, publish, and distribute this file as you see fit. WARNING - This library is _highly_ experimental and features may not work as expected. - This also means that many functions are not documented. CREDITS Written by Ginger Bill */ #ifndef GBGL_INCLUDE_GB_GL_H #define GBGL_INCLUDE_GB_GL_H #ifndef GB_IMPLEMENTATION #include "gb.h" #endif #ifndef GB_MATH_IMPLEMENTATION #include "gb_math.h" #endif #ifndef STB_IMAGE_IMPLEMENTATION #include "stb_image.h" #endif #if defined(__cplusplus) extern "C" { #endif #ifndef GBGL_DEF #define GBGL_DEF extern #endif #ifndef gbgl_malloc #define gbgl_malloc(sz) malloc(sz) #endif #ifndef gbgl_free #define gbgl_free(ptr) free(ptr) #endif //////////////////////////////////////////////////////////////// // // Generic Stuff // // #ifndef GBGL_VERT_PTR_AA_GENERIC #define GBGL_VERT_PTR_AA_GENERIC // NOTE(bill) The "default" is just the f32 version #define gbgl_vert_ptr_aa(index, element_count, Type, var_name) \ gbgl_vert_ptr_aa_f32(index, element_count, Type, var_name) #define gbgl_vert_ptr_aa_f32(index, element_count, Type, var_name) do { \ glVertexAttribPointer(index, \ element_count, \ GL_FLOAT, \ false, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #define gbgl_vert_ptr_aa_u8(index, element_count, Type, var_name) do { \ glVertexAttribPointer(index, \ element_count, \ GL_UNSIGNED_BYTE, \ false, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #define gbgl_vert_ptr_aa_u8n(index, element_count, Type, var_name) do { \ glVertexAttribPointer(index, \ element_count, \ GL_UNSIGNED_BYTE, \ true, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #define gbgl_vert_ptr_aa_u32(index, element_count, Type, var_name) do { \ glVertexAttribIPointer(index, \ element_count, \ GL_UNSIGNED_INT, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #define gbgl_vert_ptr_aa_u16(index, element_count, Type, var_name) do { \ glVertexAttribIPointer(index, \ element_count, \ GL_UNSIGNED_SHORT, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #define gbgl_vert_ptr_aa_u16n(index, element_count, Type, var_name) do { \ glVertexAttribPointer(index, \ element_count, \ GL_UNSIGNED_SHORT, \ true, \ gb_size_of(Type), \ (void const *)(gb_offset_of(Type, var_name))); \ glEnableVertexAttribArray(index); \ } while (0) #endif GBGL_DEF u32 gbgl_generate_sampler(u32 min_filter, u32 max_filter, u32 s_wrap, u32 t_wrap); //////////////////////////////////////////////////////////////// // // Data Buffers // // typedef enum gbglBufferDataType { GBGL_BDT_U8 = GL_UNSIGNED_BYTE, GBGL_BDT_I8 = GL_BYTE, GBGL_BDT_U16 = GL_UNSIGNED_SHORT, GBGL_BDT_I16 = GL_SHORT, GBGL_BDT_F16 = GL_HALF_FLOAT, GBGL_BDT_U32 = GL_UNSIGNED_INT, GBGL_BDT_I32 = GL_INT, GBGL_BDT_F32 = GL_FLOAT, GBGL_BDT_F8, // NOTE(bill): This is not a "real" OpenGL type but it is needed for internal format enums } gbglBufferDataType; // NOTE(bill) index+1 = channels count #if defined(GBGL_USE_SRGB_TEXTURE_FORMAT) i32 const GBGL_TEXTURE_FORMAT[4] = { GL_RED, GL_RG, GL_SRGB8, GL_SRGB8_ALPHA8 }; #else i32 const GBGL_TEXTURE_FORMAT[4] = { GL_RED, GL_RG, GL_RGB, GL_RGBA }; #endif i32 const GBGL_INTERNAL_TEXTURE_FORMAT_8[4] = { GL_R8, GL_RG8, GL_RGB8, GL_RGBA8 }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_16[4] = { GL_R16, GL_RG16, GL_RGB16, GL_RGBA16 }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_32[4] = { GL_R32F, GL_RG32F, GL_RGB32F, GL_RGBA32F }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_U8[4] = { GL_R8UI, GL_RG8UI, GL_RGB8UI, GL_RGB8UI }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_I8[4] = { GL_R8I, GL_RG8I, GL_RGB8I, GL_RGB8I }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_F8[4] = { GL_R8, GL_RG8, GL_RGB8, GL_RGB8 }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_U16[4] = { GL_R16UI, GL_RG16UI, GL_RGB16UI, GL_RGB16UI }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_I16[4] = { GL_R16I, GL_RG16I, GL_RGB16I, GL_RGB16I }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_F16[4] = { GL_R16F, GL_RG16F, GL_RGB16F, GL_RGB16F }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_U32[4] = { GL_R32UI, GL_RG32UI, GL_RGB32UI, GL_RGBA32UI }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_I32[4] = { GL_R32I, GL_RG32I, GL_RGB32I, GL_RGBA32I }; i32 const GBGL_INTERNAL_TEXTURE_FORMAT_F32[4] = { GL_R32F, GL_RG32F, GL_RGB32F, GL_RGBA32F }; gb_inline i32 gbgl__get_texture_format(gbglBufferDataType data_type, i32 channel_count) { GB_ASSERT(channel_count >= 1 && channel_count <= 4); switch (data_type) { case GBGL_BDT_U8: return GBGL_INTERNAL_TEXTURE_FORMAT_U8[channel_count-1]; case GBGL_BDT_I8: return GBGL_INTERNAL_TEXTURE_FORMAT_I8[channel_count-1]; case GBGL_BDT_F8: return GBGL_INTERNAL_TEXTURE_FORMAT_F8[channel_count-1]; case GBGL_BDT_U16: return GBGL_INTERNAL_TEXTURE_FORMAT_U16[channel_count-1]; case GBGL_BDT_I16: return GBGL_INTERNAL_TEXTURE_FORMAT_I16[channel_count-1]; case GBGL_BDT_F16: return GBGL_INTERNAL_TEXTURE_FORMAT_F16[channel_count-1]; case GBGL_BDT_U32: return GBGL_INTERNAL_TEXTURE_FORMAT_U32[channel_count-1]; case GBGL_BDT_I32: return GBGL_INTERNAL_TEXTURE_FORMAT_I32[channel_count-1]; case GBGL_BDT_F32: return GBGL_INTERNAL_TEXTURE_FORMAT_F32[channel_count-1]; } return GBGL_INTERNAL_TEXTURE_FORMAT_F32[4-1]; } typedef struct gbglTBO { u32 buffer_obj_handle; u32 buffer_handle; } gbglTBO; // NOTE(bill): usage_hint == (GL_STATIC_DRAW, GL_STREAM_DRAW, GL_DYNAMIC_DRAW) GBGL_DEF u32 gbgl_make_vbo(void const *data, isize size, i32 usage_hint); GBGL_DEF u32 gbgl_make_ebo(void const *data, isize size, i32 usage_hint); GBGL_DEF gbglTBO gbgl_make_tbo(gbglBufferDataType data_type, i32 channel_count, void const *data, isize size, i32 usage_hint); GBGL_DEF void gbgl_vbo_copy(u32 vbo_handle, void *const data, isize size, isize offset); GBGL_DEF void gbgl_ebo_copy(u32 ebo_handle, void *const data, isize size, isize offset); GBGL_DEF void gbgl_tbo_copy(gbglTBO tbo, void *const data, isize size, isize offset); GBGL_DEF void gbgl_bind_vbo(u32 vbo_handle); GBGL_DEF void gbgl_bind_ebo(u32 ebo_handle); GBGL_DEF void gbgl_bind_tbo(gbglTBO tbo, i32 sampler_handle, i32 tex_unit); // NOTE(bill): access = GL_WRITE_ONLY, etc. GBGL_DEF void *gbgl_map_vbo(u32 vbo_handle, i32 access); GBGL_DEF void *gbgl_map_ebo(u32 ebo_handle, i32 access); GBGL_DEF void gbgl_unmap_vbo(void); GBGL_DEF void gbgl_unmap_ebo(void); //////////////////////////////////////////////////////////////// // // Shader // // typedef enum gbglShaderType { GBGL_SHADER_TYPE_VERTEX, GBGL_SHADER_TYPE_FRAGMENT, GBGL_SHADER_TYPE_GEOMETRY, GBGL_SHADER_TYPE_COUNT, } gbglShaderType; i32 const GBGL_SHADER_TYPE[GBGL_SHADER_TYPE_COUNT] = { GL_VERTEX_SHADER, /* GBGL_SHADER_TYPE_VERTEX */ GL_FRAGMENT_SHADER, /* GBGL_SHADER_TYPE_FRAGMENT */ GL_GEOMETRY_SHADER, /* GBGL_SHADER_TYPE_GEOMETRY */ }; typedef enum gbglShaderError { GBGL_SHADER_ERROR_NONE, GBGL_SHADER_ERROR_SHADER_COMPILE, GBGL_SHADER_ERROR_LINKING, GBGL_SHADER_ERROR_UNABLE_TO_READ_FILE, GBGL_SHADER_ERROR_COUNT, } gbglShaderError; #ifndef GBGL_MAX_UNIFORM_COUNT #define GBGL_MAX_UNIFORM_COUNT 32 #endif typedef struct gbglShader { u32 shaders[GBGL_SHADER_TYPE_COUNT]; u32 program; i32 uniform_locs[GBGL_MAX_UNIFORM_COUNT]; char *uniform_names[GBGL_MAX_UNIFORM_COUNT]; i32 uniform_count; u32 type_flags; gbFile files[GBGL_SHADER_TYPE_COUNT]; char base_name[64]; } gbglShader; #ifndef GBGL_SHADER_FILE_EXTENSIONS_DEFINED #define GBGL_SHADER_FILE_EXTENSIONS_DEFINED gb_global char const *GBGL_SHADER_FILE_EXTENSIONS[GBGL_SHADER_TYPE_COUNT] = {".vs", ".fs", ".gs"}; #endif GBGL_DEF gbglShaderError gbgl_load_shader_from_file (gbglShader *s, u32 type_bits, char const *filename, ...); GBGL_DEF gbglShaderError gbgl_load_shader_vf_from_source (gbglShader *s, char const *vert_source, char const *frag_source); GBGL_DEF gbglShaderError gbgl_load_shader_vfg_from_source(gbglShader *s, char const *vert_source, char const *frag_source, char const *geom_source); GBGL_DEF void gbgl_destroy_shader(gbglShader *shader); GBGL_DEF b32 gbgl_has_shader_changed(gbglShader *shader); GBGL_DEF b32 gbgl_reload_shader(gbglShader *shader); // TODO(bill): Return an error code? GBGL_DEF void gbgl_use_shader(gbglShader *shader); GBGL_DEF b32 gbgl_is_shader_in_use(gbglShader *shader); GBGL_DEF i32 gbgl_get_uniform(gbglShader *shader, char const *name); #ifndef GBGL_UNIFORM_SET #define GBGL_UNIFORM_SET #define gbgl_set_uniform_int(loc, i) glUniform1i(loc, i) #define gbgl_set_uniform_float(loc, f) glUniform1f(loc, f) #define gbgl_set_uniform_vec2(loc, v) glUniform2fv(loc, 1, &v.x) #define gbgl_set_uniform_vec3(loc, v) glUniform3fv(loc, 1, &v.x) #define gbgl_set_uniform_vec4(loc, v) glUniform4fv(loc, 1, &v.x) #define gbgl_set_uniform_mat4(loc, mat) glUniformMatrix4fv(loc, 1, false, mat) #define gbgl_set_uniform_mat4_count(loc, mat, count) glUniformMatrix4fv(loc, count, false, mat) #endif //////////////////////////////////////////////////////////////// // // Texture // // typedef enum gbglTextureType { GBGL_TEXTURE_TYPE_2D, GBGL_TEXTURE_TYPE_CUBE_MAP, GBGL_TEXTURE_TYPE_COUNT, } gbglTextureType; gb_global i32 const GBGL_TEXTURE_TYPE[GBGL_TEXTURE_TYPE_COUNT] = { GL_TEXTURE_2D, /* GBGL_TEXTURE_TYPE_2D */ GL_TEXTURE_CUBE_MAP, /* GBGL_TEXTURE_TYPE_CUBE_MAP */ }; typedef struct gbglTexture { i32 width, height; i32 channel_count; gbglBufferDataType data_type; gbglTextureType type; u32 handle; } gbglTexture; GBGL_DEF b32 gbgl_load_texture2d_from_file(gbglTexture *texture, b32 flip_vertically, char const *filename, ...); GBGL_DEF b32 gbgl_load_texture2d_from_memory(gbglTexture *texture, void const *data, i32 width, i32 height, i32 channel_count); GBGL_DEF b32 gbgl_init_texture2d_coloured(gbglTexture *texture, gbColour colour); GBGL_DEF void gbgl_destroy_texture(gbglTexture *texture); GBGL_DEF void gbgl_bind_texture2d(gbglTexture const *texture, u32 position, u32 sampler); //////////////////////////////////////////////////////////////// // // Render Buffer // // // TODO(bill): Record depth and stencil and numerous colour attachments typedef struct gbglRenderBuffer { i32 width, height; i32 channel_count; u32 handle; gbglTexture colour_texture; } gbglRenderBuffer; #define GBGL_MAX_RENDER_COLOUR_BUFFERS 16 gb_global u32 const GBGL_COLOUR_BUFFER_ATTACHMENTS[GBGL_MAX_RENDER_COLOUR_BUFFERS] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3, GL_COLOR_ATTACHMENT4, GL_COLOR_ATTACHMENT5, GL_COLOR_ATTACHMENT6, GL_COLOR_ATTACHMENT7, GL_COLOR_ATTACHMENT8, GL_COLOR_ATTACHMENT9, GL_COLOR_ATTACHMENT10, GL_COLOR_ATTACHMENT11, GL_COLOR_ATTACHMENT12, GL_COLOR_ATTACHMENT13, GL_COLOR_ATTACHMENT14, GL_COLOR_ATTACHMENT15, }; GBGL_DEF b32 gbgl_init_render_buffer(gbglRenderBuffer *rb, i32 width, i32 height, i32 channel_count); GBGL_DEF void gbgl_destroy_render_buffer(gbglRenderBuffer *rb); GBGL_DEF void gbgl_render_to_buffer(gbglRenderBuffer const *rb); GBGL_DEF void gbgl_render_to_screen(i32 width, i32 height); //////////////////////////////////////////////////////////////// // // Basic State // // typedef struct gbglBasicVertex { f32 x, y; f32 u, v; } gbglBasicVertex; #ifndef GBGL_BS_MAX_VERTEX_COUNT #define GBGL_BS_MAX_VERTEX_COUNT 32 #endif #ifndef GBGL_BS_MAX_INDEX_COUNT #define GBGL_BS_MAX_INDEX_COUNT 6 #endif typedef struct gbglBasicState { gbglBasicVertex vertices[GBGL_BS_MAX_VERTEX_COUNT]; u16 indices[GBGL_BS_MAX_INDEX_COUNT]; u32 vao, vbo, ebo; u32 nearest_sampler; u32 linear_sampler; gbglShader ortho_tex_shader; gbglShader ortho_col_shader; gbMat4 ortho_mat; i32 width, height; } gbglBasicState; GBGL_DEF void gbgl_bs_init(gbglBasicState *bs, i32 window_width, i32 window_height); GBGL_DEF void gbgl_bs_set_resolution(gbglBasicState *bs, i32 window_width, i32 window_height); GBGL_DEF void gbgl_bs_begin(gbglBasicState *bs, i32 window_width, i32 window_height); GBGL_DEF void gbgl_bs_end(gbglBasicState *bs); GBGL_DEF void gbgl_bs_draw_textured_rect(gbglBasicState *bs, gbglTexture *tex, gbVec2 pos, gbVec2 dim, b32 v_up); GBGL_DEF void gbgl_bs_draw_rect(gbglBasicState *bs, gbVec2 pos, gbVec2 dim, gbColour col); GBGL_DEF void gbgl_bs_draw_outlined_rect(gbglBasicState *bs, gbVec2 pos, gbVec2 dim, gbColour col, f32 thickness); GBGL_DEF void gbgl_bs_draw_quad(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbVec2 p2, gbVec2 p3, gbColour col); GBGL_DEF void gbgl_bs_draw_outlined_quad(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbVec2 p2, gbVec2 p3, gbColour col, f32 thickness); GBGL_DEF void gbgl_bs_draw_line(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbColour col, f32 thickness); GBGL_DEF void gbgl_bs_draw_circle(gbglBasicState *bs, gbVec2 p, f32 radius, gbColour col); GBGL_DEF void gbgl_bs_draw_outlined_circle(gbglBasicState *bs, gbVec2 p, f32 radius, gbColour col, f32 thickness); #if defined(__cplusplus) } #endif #endif //////////////////////////////////////////////////////////////// // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // Implementation // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // // //////////////////////////////////////////////////////////////// #if defined(GBGL_IMPLEMENTATION) u32 gbgl_generate_sampler(u32 min_filter, u32 max_filter, u32 s_wrap, u32 t_wrap) { u32 samp; glGenSamplers(1, &samp); glSamplerParameteri(samp, GL_TEXTURE_MIN_FILTER, min_filter); glSamplerParameteri(samp, GL_TEXTURE_MAG_FILTER, max_filter); glSamplerParameteri(samp, GL_TEXTURE_WRAP_S, s_wrap); glSamplerParameteri(samp, GL_TEXTURE_WRAP_T, t_wrap); return samp; } //////////////////////////////////////////////////////////////// // // Data Buffers // // gb_inline u32 gbgl__make_buffer(isize size, void const *data, i32 target, i32 usage_hint) { u32 buffer_handle; glGenBuffers(1, &buffer_handle); glBindBuffer(target, buffer_handle); glBufferData(target, size, data, usage_hint); return buffer_handle; } gb_inline void gbgl__buffer_copy(u32 buffer_handle, i32 target, void const *data, isize size, isize offset) { glBindBuffer(target, buffer_handle); glBufferSubData(target, offset, size, data); } // NOTE(bill): usage_hint == (GL_STATIC_DRAW, GL_STREAM_DRAW, GL_DYNAMIC_DRAW) gb_inline u32 gbgl_make_vbo(void const *data, isize size, i32 usage_hint) { return gbgl__make_buffer(size, data, GL_ARRAY_BUFFER, usage_hint); } gb_inline u32 gbgl_make_ebo(void const *data, isize size, i32 usage_hint) { return gbgl__make_buffer(size, data, GL_ELEMENT_ARRAY_BUFFER, usage_hint); } gb_inline gbglTBO gbgl_make_tbo(gbglBufferDataType data_type, i32 channel_count, void const *data, isize size, i32 usage_hint) { gbglTBO tbo; i32 internal_format; tbo.buffer_obj_handle = gbgl__make_buffer(size, data, GL_TEXTURE_BUFFER, usage_hint); glGenTextures(1, &tbo.buffer_handle); glBindTexture(GL_TEXTURE_BUFFER, tbo.buffer_handle); internal_format = gbgl__get_texture_format(data_type, channel_count); glTexBuffer(GL_TEXTURE_BUFFER, internal_format, tbo.buffer_obj_handle); return tbo; } gb_inline void gbgl_vbo_copy(u32 vbo_handle, void *const data, isize size, isize offset) { gbgl__buffer_copy(vbo_handle, GL_ARRAY_BUFFER, data, size, offset); } gb_inline void gbgl_ebo_copy(u32 ebo_handle, void *const data, isize size, isize offset) { gbgl__buffer_copy(ebo_handle, GL_ELEMENT_ARRAY_BUFFER, data, size, offset); } gb_inline void gbgl_tbo_copy(gbglTBO tbo, void *const data, isize size, isize offset) { gbgl__buffer_copy(tbo.buffer_obj_handle, GL_TEXTURE_BUFFER, data, size, offset); } gb_inline void gbgl_bind_vbo(u32 vbo_handle) { glBindBuffer(GL_ARRAY_BUFFER, vbo_handle); } gb_inline void gbgl_bind_ebo(u32 ebo_handle) { glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo_handle); } gb_inline void gbgl_bind_tbo(gbglTBO tbo, i32 sampler_handle, i32 tex_unit) { glActiveTexture(GL_TEXTURE0 + tex_unit); glBindTexture(GL_TEXTURE_BUFFER, tbo.buffer_handle); glBindSampler(0, sampler_handle); } // NOTE(bill): access = GL_WRITE_ONLY, etc. gb_inline void * gbgl_map_vbo(u32 vbo_handle, i32 access) { gbgl_bind_vbo(vbo_handle); return glMapBuffer(GL_ARRAY_BUFFER, access); } gb_inline void * gbgl_map_ebo(u32 ebo_handle, i32 access) { gbgl_bind_ebo(ebo_handle); return glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, access); } gb_inline void gbgl_unmap_vbo(void) { glUnmapBuffer(GL_ARRAY_BUFFER); } gb_inline void gbgl_unmap_ebo(void) { glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER); } //////////////////////////////////////////////////////////////// // // Shader // // gbglShaderError gbgl__load_single_shader_from_file(gbglShader *shader, gbglShaderType type, char const *name) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; if (!gb_open_file(&shader->files[type], "%s%s", name, GBGL_SHADER_FILE_EXTENSIONS[type])) { err = GBGL_SHADER_ERROR_UNABLE_TO_READ_FILE; } else { gb_local_persist char info_log[4096]; i64 file_size = gb_file_size(&shader->files[type]); char *file_source = cast(char *)gbgl_malloc(file_size+1); // TODO(bill): LOG MALLOC USAGE GB_ASSERT_NOT_NULL(file_source); if (file_source) { i32 params; gb_file_read_at(&shader->files[type], file_source, file_size, 0); file_source[file_size] = '\0'; shader->shaders[type] = glCreateShader(GBGL_SHADER_TYPE[type]); glShaderSource(shader->shaders[type], 1, &file_source, NULL); glCompileShader(shader->shaders[type]); glGetShaderiv(shader->shaders[type], GL_COMPILE_STATUS, ¶ms); if (!params) { gb_fprintf(stderr, "Shader Source:\n%s\n", file_source); glGetShaderInfoLog(shader->shaders[type], gb_size_of(info_log), NULL, info_log); gb_fprintf(stderr, "Shader compilation failed:\n %s\n", info_log); err = GBGL_SHADER_ERROR_SHADER_COMPILE; } gbgl_free(file_source); } gb_close_file(&shader->files[type]); } return err; } gbglShaderError gbgl__load_single_shader_from_source(gbglShader *s, gbglShaderType type, char const *text) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; i32 status; s->shaders[type] = glCreateShader(GBGL_SHADER_TYPE[type]); glShaderSource(s->shaders[type], 1, &text, 0); glCompileShader(s->shaders[type]); glGetShaderiv(s->shaders[type], GL_COMPILE_STATUS, &status); if (!status) { gb_local_persist char log_info[4096]; i32 total_len, log_len; gb_fprintf(stderr, "Unable to compile shader: %s\n", text); glGetShaderiv(s->shaders[type], GL_INFO_LOG_LENGTH, &status); total_len = status; glGetShaderInfoLog(s->shaders[type], 4095, &log_len, log_info); gb_fprintf(stderr, log_info); err = GBGL_SHADER_ERROR_SHADER_COMPILE; } return err; } gbglShaderError gbgl__link_shader(gbglShader *shader) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; i32 i, status; shader->program = glCreateProgram(); for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (shader->type_flags & GB_BIT(i)) glAttachShader(shader->program, shader->shaders[i]); } glLinkProgram(shader->program); glGetProgramiv(shader->program, GL_LINK_STATUS, &status); if (!status) { gb_local_persist char log_info[4096]; glGetProgramInfoLog(shader->program, gb_size_of(log_info), NULL, log_info); gb_fprintf(stderr, "Shader linking failed:\n %s \n", log_info); err = GBGL_SHADER_ERROR_LINKING; } for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (shader->type_flags & GB_BIT(i)) glDetachShader(shader->program, shader->shaders[i]); } return err; } gbglShaderError gbgl_load_shader_from_file(gbglShader *shader, u32 type_bits, char const *filename, ...) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; b32 loaded_shader[GBGL_SHADER_TYPE_COUNT] = {0}; i32 i; gb_zero_struct(shader); shader->type_flags = type_bits; gb_strncpy(shader->base_name, filename, gb_size_of(shader->base_name)); for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (type_bits & GB_BIT(i)) { err = gbgl__load_single_shader_from_file(shader, cast(gbglShaderType)i, filename); if (err != GBGL_SHADER_ERROR_NONE) return err; loaded_shader[i] = true; } } err = gbgl__link_shader(shader); return err; } gbglShaderError gbgl_load_shader_vf_from_source(gbglShader *s, char const *vert_source, char const *frag_source) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; gb_zero_struct(s); s->type_flags = GB_BIT(GBGL_SHADER_TYPE_VERTEX) | GB_BIT(GBGL_SHADER_TYPE_FRAGMENT); err = gbgl__load_single_shader_from_source(s, GBGL_SHADER_TYPE_VERTEX, vert_source); if (err != GBGL_SHADER_ERROR_NONE) return err; err = gbgl__load_single_shader_from_source(s, GBGL_SHADER_TYPE_FRAGMENT, frag_source); if (err != GBGL_SHADER_ERROR_NONE) return err; err = gbgl__link_shader(s); return err; } gbglShaderError gbgl_load_shader_vfg_from_source(gbglShader *s, char const *vert_source, char const *frag_source, char const *geom_source) { gbglShaderError err = GBGL_SHADER_ERROR_NONE; gb_zero_struct(s); s->type_flags = GB_BIT(GBGL_SHADER_TYPE_VERTEX) | GB_BIT(GBGL_SHADER_TYPE_FRAGMENT) | GB_BIT(GBGL_SHADER_TYPE_GEOMETRY); err = gbgl__load_single_shader_from_source(s, GBGL_SHADER_TYPE_VERTEX, vert_source); if (err != GBGL_SHADER_ERROR_NONE) return err; err = gbgl__load_single_shader_from_source(s, GBGL_SHADER_TYPE_FRAGMENT, frag_source); if (err != GBGL_SHADER_ERROR_NONE) return err; err = gbgl__load_single_shader_from_source(s, GBGL_SHADER_TYPE_GEOMETRY, geom_source); if (err != GBGL_SHADER_ERROR_NONE) return err; err = gbgl__link_shader(s); return err; } gb_inline void gbgl_destroy_shader(gbglShader *shader) { i32 i; for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (shader->type_flags & GB_BIT(i)) { gb_close_file(&shader->files[i]); glDeleteShader(shader->shaders[i]); } } glDeleteProgram(shader->program); for (i = 0; i < shader->uniform_count; i++) { gbgl_free(shader->uniform_names[i]); } } gb_inline b32 gbgl_has_shader_changed(gbglShader *shader) { i32 i; for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (shader->type_flags & GB_BIT(i)) { if (gb_has_file_changed(&shader->files[i])) { return true; } } } return false; } b32 gbgl_reload_shader(gbglShader *shader) { i32 i; for (i = 0; i < GBGL_SHADER_TYPE_COUNT; i++) { if (shader->type_flags & GB_BIT(i)) { if (gbgl__load_single_shader_from_file(shader, cast(gbglShaderType)i, shader->base_name) != GBGL_SHADER_ERROR_NONE) return false; } } if (gbgl__link_shader(shader) != GBGL_SHADER_ERROR_NONE) return false; for (i = 0; i < shader->uniform_count; i++) shader->uniform_locs[i] = glGetUniformLocation(shader->program, shader->uniform_names[i]); return true; } gb_inline void gbgl_use_shader(gbglShader *s) { glUseProgram(s ? s->program : 0); } gb_inline b32 gbgl_is_shader_in_use(gbglShader *s) { if (s) { i32 curr = 0; glGetIntegerv(GL_CURRENT_PROGRAM, &curr); return (curr == cast(i32)s->program); } return false; } i32 gbgl_get_uniform(gbglShader *s, char const *name) { i32 i, loc = -1; for (i = 0; i < s->uniform_count; i++) { if (gb_strcmp(s->uniform_names[i], name) == 0) { return s->uniform_locs[i]; } } GB_ASSERT_MSG(s->uniform_count < GBGL_MAX_UNIFORM_COUNT, "Uniform array for shader is full"); loc = glGetUniformLocation(s->program, name); s->uniform_names[s->uniform_count] = gb_alloc_cstring(gb_heap_allocator(), name); s->uniform_locs[s->uniform_count] = loc; s->uniform_count++; return loc; } //////////////////////////////////////////////////////////////// // // Render Buffer // // #if 0 b32 gbgl_render_buffer_init(gbglRenderBuffer *in_out_rb) { i32 i; if (in_out_rb->colour_buffer_count >= GBGL_MAX_RENDER_COLOUR_BUFFERS) { return false; } glGenFramebuffers(1, &in_out_rb->gl_frame_buffer_handle); glBindFramebuffer(GL_FRAMEBUFFER, in_out_rb->gl_frame_buffer_handle); glGenTextures(in_out_rb->colour_buffer_count, in_out_rb->handles); for (i = 0; i < in_out_rb->colour_buffer_count; i++) { i32 channel_count = in_out_rb->channel_count[i]; glBindTexture(GL_TEXTURE_2D, in_out_rb->handles[i]); glTexImage2D(GL_TEXTURE_2D, 0, GBGL_INTERNAL_TEXTURE_FORMAT_8[channel_count-1], in_out_rb->width, in_out_rb->height, 0, GBGL_TEXTURE_FORMAT[channel_count-1], in_out_rb->data_type[0], 0); glBindTexture(GL_TEXTURE_2D, 0); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, in_out_rb->handles[0], 0); } glDrawBuffers(in_out_rb->colour_buffer_count, GBGL_COLOUR_BUFFER_ATTACHMENTS); //@TODO: not every valid permutation has been tested, it's likely that there's a format/internal format mismatch somewhere if (in_out_rb->has_depth || in_out_rb->has_stencil) { if (in_out_rb->has_depth && in_out_rb->has_stencil) { glGenRenderbuffers(1, &in_out_rb->gl_depth_stencil_buffer_handle); glBindRenderbuffer(GL_RENDERBUFFER, in_out_rb->gl_depth_stencil_buffer_handle); glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, in_out_rb->width, in_out_rb->height); glBindRenderbuffer(GL_RENDERBUFFER, 0); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, in_out_rb->gl_depth_stencil_buffer_handle); } else if (in_out_rb->has_depth) { glGenRenderbuffers(1, &in_out_rb->gl_depth_stencil_buffer_handle); glBindRenderbuffer(GL_RENDERBUFFER, in_out_rb->gl_depth_stencil_buffer_handle); glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, in_out_rb->width, in_out_rb->height); glBindRenderbuffer(GL_RENDERBUFFER, 0); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, in_out_rb->gl_depth_stencil_buffer_handle); } else if (in_out_rb->has_stencil) { GB_PANIC("A framebuffer cannot have a stencil without depth"); // NOTE(bill): no stencil w/o depth } } in_out_rb->gl_frame_buffer_status = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (in_out_rb->gl_frame_buffer_status != GL_FRAMEBUFFER_COMPLETE) { gb_fprintf(stderr, "Unable to create OpenGL Frame buffer. Frame buffer incomplete: %d\n", in_out_rb->gl_frame_buffer_status); } glBindFramebuffer(GL_FRAMEBUFFER, 0); return in_out_rb->gl_frame_buffer_status == GL_FRAMEBUFFER_COMPLETE; } #endif b32 gbgl_init_render_buffer(gbglRenderBuffer *rb, i32 width, i32 height, i32 channel_count) { if ((rb->width == width) && (rb->height == height) && (rb->channel_count == channel_count)) return true; gbgl_destroy_render_buffer(rb); gb_zero_struct(rb); rb->width = width; rb->height = height; glEnable(GL_FRAMEBUFFER_SRGB); glGenFramebuffers(1, &rb->handle); glBindFramebuffer(GL_FRAMEBUFFER, rb->handle); gbgl_load_texture2d_from_memory(&rb->colour_texture, NULL, width, height, channel_count); glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, rb->colour_texture.handle, 0); glBindTexture(GL_TEXTURE_2D, 0); glBindFramebuffer(GL_FRAMEBUFFER, 0); { u32 draw_buffers[] = {GL_COLOR_ATTACHMENT0}; glDrawBuffers(gb_count_of(draw_buffers), draw_buffers); } { u32 status = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (status != GL_FRAMEBUFFER_COMPLETE) { gb_fprintf(stderr, "Framebuffer Status: 0x%x\n", status); return false; } } return true; } gb_inline void gbgl_destroy_render_buffer(gbglRenderBuffer *rb) { if (rb->handle) glDeleteFramebuffers(1, &rb->handle); gbgl_destroy_texture(&rb->colour_texture); } gb_inline void gbgl_render_to_buffer(gbglRenderBuffer const *rb) { GB_ASSERT_NOT_NULL(rb); glViewport(0, 0, rb->width, rb->height); glBindFramebuffer(GL_FRAMEBUFFER, rb->handle); } gb_inline void gbgl_render_to_screen(i32 width, i32 height) { glViewport(0, 0, width, height); glBindFramebuffer(GL_FRAMEBUFFER, 0); } //////////////////////////////////////////////////////////////// // // Texture // // b32 gbgl_load_texture2d_from_memory(gbglTexture *tex, void const *data, i32 width, i32 height, i32 channel_count) { b32 result = true; gb_zero_struct(tex); tex->width = width; tex->height = height; tex->channel_count = channel_count; tex->data_type = GBGL_BDT_U8; tex->type = GBGL_TEXTURE_TYPE_2D; glGenTextures(1, &tex->handle); glBindTexture(GL_TEXTURE_2D, tex->handle); glTexImage2D(GL_TEXTURE_2D, 0, GBGL_INTERNAL_TEXTURE_FORMAT_8[channel_count-1], width, height, 0, GBGL_TEXTURE_FORMAT[channel_count-1], GL_UNSIGNED_BYTE, data); glBindTexture(GL_TEXTURE_2D, 0); glGenerateMipmap(GL_TEXTURE_2D); glFinish(); return result; } b32 gbgl_load_texture2d_from_file(gbglTexture *texture, b32 flip_vertically, char const *filename, ...) { b32 result; u8 *data; int width, height, comp; char *path; va_list va; va_start(va, filename); path = gb_sprintf_va(filename, va); va_end(va); stbi_set_flip_vertically_on_load(flip_vertically); data = stbi_load(path, &width, &height, &comp, 0); if (data == NULL) { gb_fprintf(stderr, "Failed to load image: %s\n", path); result = false; } else { result = gbgl_load_texture2d_from_memory(texture, data, width, height, comp); stbi_image_free(data); } return result; } gb_inline b32 gbgl_make_texture2d_coloured(gbglTexture *t, gbColour colour) { return gbgl_load_texture2d_from_memory(t, &colour.rgba, 1, 1, 4); } void gbgl_bind_texture2d(gbglTexture const *t, u32 position, u32 sampler) { GB_ASSERT(t->type == GBGL_TEXTURE_TYPE_2D); if (position > 31) { position = 31; gb_fprintf(stderr, "Textures can only bound to position [0 ... 31]\n"); gb_fprintf(stderr, "Will bind to position [31]\n"); } glActiveTexture(GL_TEXTURE0 + position); glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, t ? t->handle : 0); glBindSampler(position, sampler); } gb_inline void gbgl_destroy_texture(gbglTexture *t) { if (t->handle) { glDeleteTextures(1, &t->handle); } } //////////////////////////////////////////////////////////////// // // Basic State // // void gbgl_bs_init(gbglBasicState *bs, i32 window_width, i32 window_height) { isize i; gbgl_bs_set_resolution(bs, window_width, window_height); glGenVertexArrays(1, &bs->vao); glBindVertexArray(bs->vao); bs->vbo = gbgl_make_vbo(NULL, gb_size_of(gbglBasicVertex) * GBGL_BS_MAX_VERTEX_COUNT, GL_DYNAMIC_DRAW); for (i = 0; i < GBGL_BS_MAX_INDEX_COUNT / 6; i++) { bs->indices[i*6 + 0] = i*4 + 0; bs->indices[i*6 + 1] = i*4 + 1; bs->indices[i*6 + 2] = i*4 + 2; bs->indices[i*6 + 3] = i*4 + 2; bs->indices[i*6 + 4] = i*4 + 3; bs->indices[i*6 + 5] = i*4 + 0; } bs->ebo = gbgl_make_ebo(bs->indices, gb_size_of(u16) * GBGL_BS_MAX_INDEX_COUNT, GL_STATIC_DRAW); bs->nearest_sampler = gbgl_generate_sampler(GL_NEAREST, GL_NEAREST, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE); bs->linear_sampler = gbgl_generate_sampler(GL_LINEAR, GL_LINEAR, GL_CLAMP_TO_EDGE, GL_CLAMP_TO_EDGE); gbgl_load_shader_vf_from_source(&bs->ortho_tex_shader, "#version 410 core\n" "layout (location = 0) in vec4 a_position;\n" "layout (location = 1) in vec2 a_tex_coord;\n" "uniform mat4 u_ortho_mat;\n" "out vec2 v_tex_coord;\n" "void main(void) {\n" " gl_Position = u_ortho_mat * a_position;\n" " v_tex_coord = a_tex_coord;\n" "}\n", "#version 410 core\n" "precision mediump float;" "in vec2 v_tex_coord;\n" "layout (binding = 0) uniform sampler2D u_tex;\n" "out vec4 o_colour;\n" "void main(void) {\n" " o_colour = texture2D(u_tex, v_tex_coord);\n" "}\n"); gbgl_load_shader_vf_from_source(&bs->ortho_col_shader, "#version 410 core\n" "precision mediump float;" "layout (location = 0) in vec4 a_position;\n" "uniform mat4 u_ortho_mat;\n" "void main(void) {\n" " gl_Position = u_ortho_mat * a_position;\n" "}\n", "#version 410 core\n" "uniform vec4 u_colour;\n" "out vec4 o_colour;\n" "void main(void) {\n" " o_colour = u_colour;\n" "}\n"); } void gbgl_bs_set_resolution(gbglBasicState *bs, i32 window_width, i32 window_height) { bs->width = window_width; bs->height = window_height; gb_mat4_ortho2d(&bs->ortho_mat, 0, bs->width, 0, bs->height); } void gbgl_bs_begin(gbglBasicState *bs, i32 window_width, i32 window_height) { glBindVertexArray(bs->vao); glDisable(GL_SCISSOR_TEST); glDisable(GL_CULL_FACE); gbgl_bs_set_resolution(bs, window_width, window_height); } void gbgl_bs_end(gbglBasicState *bs) { glBindVertexArray(0); } void gbgl_bs_draw_textured_rect(gbglBasicState *bs, gbglTexture *tex, gbVec2 pos, gbVec2 dim, b32 v_up) { bs->vertices[0].x = pos.x; bs->vertices[0].y = pos.y; bs->vertices[0].u = 0.0f; bs->vertices[0].v = v_up ? 0.0f : 1.0f; bs->vertices[1].x = pos.x + dim.x; bs->vertices[1].y = pos.y; bs->vertices[1].u = 1.0f; bs->vertices[1].v = v_up ? 0.0f : 1.0f; bs->vertices[2].x = pos.x + dim.x; bs->vertices[2].y = pos.y + dim.y; bs->vertices[2].u = 1.0f; bs->vertices[2].v = v_up ? 1.0f : 0.0f; bs->vertices[3].x = pos.x; bs->vertices[3].y = pos.y + dim.y; bs->vertices[3].u = 0.0f; bs->vertices[3].v = v_up ? 1.0f : 0.0f; gbgl_use_shader(&bs->ortho_tex_shader); gbgl_set_uniform_mat4(gbgl_get_uniform(&bs->ortho_tex_shader, "u_ortho_mat"), bs->ortho_mat.e); gbgl_bind_texture2d(tex, 0, bs->nearest_sampler); gbgl_vbo_copy(bs->vbo, bs->vertices, 4*gb_size_of(bs->vertices[0]), 0); gbgl_vert_ptr_aa(0, 2, gbglBasicVertex, x); gbgl_vert_ptr_aa(1, 2, gbglBasicVertex, u); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bs->ebo); glEnable(GL_BLEND); glBlendEquationi(0, GL_FUNC_ADD); glBlendFunci(0, GL_ONE, GL_ONE_MINUS_SRC_ALPHA); glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, NULL); } void gbgl_bs_draw_rect(gbglBasicState *bs, gbVec2 pos, gbVec2 dim, gbColour col) { gbgl_bs_draw_quad(bs, gb_vec2(pos.x, pos.y), gb_vec2(pos.x+dim.x, pos.y), gb_vec2(pos.x+dim.x, pos.y+dim.y), gb_vec2(pos.x, pos.y+dim.y), col); } void gbgl_bs_draw_outlined_rect(gbglBasicState *bs, gbVec2 pos, gbVec2 dim, gbColour col, f32 thickness) { gbgl_bs_draw_outlined_quad(bs, gb_vec2(pos.x, pos.y), gb_vec2(pos.x+dim.x, pos.y), gb_vec2(pos.x+dim.x, pos.y+dim.y), gb_vec2(pos.x, pos.y+dim.y), col, thickness); } gb_internal void gbgl__bs_setup_ortho_colour_state(gbglBasicState *bs, isize vertex_count, gbColour col) { gbVec4 vcol = gb_vec4(col.r/255.0f, col.g/255.0f, col.b/255.0f, col.a/255.0f); gbgl_use_shader(&bs->ortho_col_shader); gbgl_set_uniform_mat4(gbgl_get_uniform(&bs->ortho_col_shader, "u_ortho_mat"), bs->ortho_mat.e); gbgl_set_uniform_vec4(gbgl_get_uniform(&bs->ortho_col_shader, "u_colour"), vcol); gbgl_vbo_copy(bs->vbo, bs->vertices, vertex_count*gb_size_of(bs->vertices[0]), 0); gbgl_vert_ptr_aa(0, 2, gbglBasicVertex, x); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bs->ebo); glDisable(GL_CULL_FACE); glEnable(GL_BLEND); glBlendEquation(GL_FUNC_ADD); glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA); } void gbgl_bs_draw_quad(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbVec2 p2, gbVec2 p3, gbColour col) { bs->vertices[0].x = p0.x; bs->vertices[0].y = p0.y; bs->vertices[1].x = p1.x; bs->vertices[1].y = p1.y; bs->vertices[2].x = p2.x; bs->vertices[2].y = p2.y; bs->vertices[3].x = p3.x; bs->vertices[3].y = p3.y; gbgl__bs_setup_ortho_colour_state(bs, 4, col); glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, NULL); } void gbgl_bs_draw_outlined_quad(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbVec2 p2, gbVec2 p3, gbColour col, f32 thickness) { bs->vertices[0].x = p0.x; bs->vertices[0].y = p0.y; bs->vertices[1].x = p1.x; bs->vertices[1].y = p1.y; bs->vertices[2].x = p2.x; bs->vertices[2].y = p2.y; bs->vertices[3].x = p3.x; bs->vertices[3].y = p3.y; gbgl__bs_setup_ortho_colour_state(bs, 4, col); glLineWidth(thickness); glDrawArrays(GL_LINE_LOOP, 0, 4); } void gbgl_bs_draw_line(gbglBasicState *bs, gbVec2 p0, gbVec2 p1, gbColour col, f32 thickness) { bs->vertices[0].x = p0.x; bs->vertices[0].y = p0.y; bs->vertices[1].x = p1.x; bs->vertices[1].y = p1.y; gbgl__bs_setup_ortho_colour_state(bs, 2, col); glLineWidth(thickness); glDrawArrays(GL_LINES, 0, 2); } void gbgl_bs_draw_circle(gbglBasicState *bs, gbVec2 p, f32 radius, gbColour col) { isize i; bs->vertices[0].x = p.x; bs->vertices[0].y = p.y; for (i = 0; i < 31; i++) { f32 t = cast(f32)i / 30.0f; f32 theta = t * GB_MATH_TAU; f32 c = gb_cos(theta); f32 s = gb_sin(theta); bs->vertices[i+1].x = p.x + c*radius; bs->vertices[i+1].y = p.y + s*radius; } gbgl__bs_setup_ortho_colour_state(bs, 32, col); glDrawArrays(GL_TRIANGLE_FAN, 0, 32); } void gbgl_bs_draw_outlined_circle(gbglBasicState *bs, gbVec2 p, f32 radius, gbColour col, f32 thickness) { isize i; for (i = 0; i < 32; i++) { f32 t = cast(f32)i / 31.0f; f32 theta = t * GB_MATH_TAU; f32 c = gb_cos(theta); f32 s = gb_sin(theta); bs->vertices[i].x = p.x + c*radius; bs->vertices[i].y = p.y + s*radius; } gbgl__bs_setup_ortho_colour_state(bs, 32, col); glLineWidth(thickness); glDrawArrays(GL_LINE_LOOP, 0, 32); } #endif