/* GameEngine and Editor by John Ryland Copyright (c) 2023 */ //////////////////////////////////////////////////////////////////////////////////// // OpenGLRenderDevice #include #include #include #include #include #include "NkOpenGLRenderDevice.h" #ifdef __APPLE__ #define NK_SHADER_VERSION "#version 150\n" #else #define NK_SHADER_VERSION "#version 300 es\n" #endif #define MAX_VERTEX_MEMORY 512 * 1024 #define MAX_ELEMENT_MEMORY 128 * 1024 #define MAX_TEXTURE_COUNT 64 // Change this as required /* =============================================================== * * DEVICE * * ===============================================================*/ struct nk_glfw_vertex { float position[2]; float uv[2]; nk_byte col[4]; }; namespace GameEngine { struct device { struct nk_buffer cmds; // temp buffer space for making list of commands in to struct nk_draw_null_texture tex_null; // 1x1 white pixel for drawing shapes GLuint vbo, vao, ebo; GLuint prog; GLuint vert_shdr; GLuint frag_shdr; GLint attrib_pos; GLint attrib_uv; GLint attrib_col; GLint uniform_tex; GLint uniform_proj; // Keep track of uploaded textures so we can free them uint8_t texCount; GLuint tex[MAX_TEXTURE_COUNT]; }; static void device_init(struct device *dev) { glewExperimental = 1; if (glewInit() != GLEW_OK) { fprintf(stderr, "Failed to setup GLEW\n"); exit(1); } GLint status; static const GLchar *vertex_shader = NK_SHADER_VERSION "uniform mat4 ProjMtx;\n" "in vec2 Position;\n" "in vec2 TexCoord;\n" "in vec4 Color;\n" "out vec2 Frag_UV;\n" "out vec4 Frag_Color;\n" "void main() {\n" " Frag_UV = TexCoord;\n" " Frag_Color = Color;\n" " gl_Position = ProjMtx * vec4(Position.xy, 0, 1);\n" "}\n"; static const GLchar *fragment_shader = NK_SHADER_VERSION "precision mediump float;\n" "uniform sampler2D Texture;\n" "in vec2 Frag_UV;\n" "in vec4 Frag_Color;\n" "out vec4 Out_Color;\n" "void main(){\n" " Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n" "}\n"; GLsizei vs = sizeof(struct nk_glfw_vertex); size_t vp = offsetof(struct nk_glfw_vertex, position); size_t vt = offsetof(struct nk_glfw_vertex, uv); size_t vc = offsetof(struct nk_glfw_vertex, col); nk_buffer_init_default(&dev->cmds); dev->prog = glCreateProgram(); dev->vert_shdr = glCreateShader(GL_VERTEX_SHADER); dev->frag_shdr = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(dev->vert_shdr, 1, &vertex_shader, 0); glCompileShader(dev->vert_shdr); glGetShaderiv(dev->vert_shdr, GL_COMPILE_STATUS, &status); assert(status == GL_TRUE); glShaderSource(dev->frag_shdr, 1, &fragment_shader, 0); glCompileShader(dev->frag_shdr); glGetShaderiv(dev->frag_shdr, GL_COMPILE_STATUS, &status); assert(status == GL_TRUE); glAttachShader(dev->prog, dev->vert_shdr); glAttachShader(dev->prog, dev->frag_shdr); glLinkProgram(dev->prog); glGetProgramiv(dev->prog, GL_LINK_STATUS, &status); assert(status == GL_TRUE); dev->uniform_tex = glGetUniformLocation(dev->prog, "Texture"); dev->uniform_proj = glGetUniformLocation(dev->prog, "ProjMtx"); dev->attrib_pos = glGetAttribLocation(dev->prog, "Position"); dev->attrib_uv = glGetAttribLocation(dev->prog, "TexCoord"); dev->attrib_col = glGetAttribLocation(dev->prog, "Color"); /* buffer setup */ glGenBuffers(1, &dev->vbo); glGenBuffers(1, &dev->ebo); glGenVertexArrays(1, &dev->vao); glBindVertexArray(dev->vao); glBindBuffer(GL_ARRAY_BUFFER, dev->vbo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo); glEnableVertexAttribArray((GLuint)dev->attrib_pos); glEnableVertexAttribArray((GLuint)dev->attrib_uv); glEnableVertexAttribArray((GLuint)dev->attrib_col); glVertexAttribPointer((GLuint)dev->attrib_pos, 2, GL_FLOAT, GL_FALSE, vs, (void*)vp); glVertexAttribPointer((GLuint)dev->attrib_uv, 2, GL_FLOAT, GL_FALSE, vs, (void*)vt); glVertexAttribPointer((GLuint)dev->attrib_col, 4, GL_UNSIGNED_BYTE, GL_TRUE, vs, (void*)vc); glBindTexture(GL_TEXTURE_2D, 0); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); glBindVertexArray(0); glEnable(GL_TEXTURE_2D); } static struct nk_image device_upload_texture(struct device *dev, const void *image, int width, int height, bool generateMips) { GLuint tex; glGenTextures(1, &tex); glBindTexture(GL_TEXTURE_2D, tex); if (dev->texCount >= MAX_TEXTURE_COUNT) { printf("ERROR: uploaded too many textures.\n" "Max configured is %i, reduce textures or update MAX_TEXTURE_COUNT and recompile.\n", MAX_TEXTURE_COUNT); } else { dev->tex[dev->texCount] = tex; dev->texCount++; } if (generateMips) { glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_NEAREST); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); } else { glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); } glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei)width, (GLsizei)height, 0, GL_RGBA, GL_UNSIGNED_BYTE, image); if (generateMips) { glGenerateMipmap(GL_TEXTURE_2D); } return nk_image_id((int)tex); } static void device_shutdown(struct device *dev) { glDetachShader(dev->prog, dev->vert_shdr); glDetachShader(dev->prog, dev->frag_shdr); glDeleteShader(dev->vert_shdr); glDeleteShader(dev->frag_shdr); glDeleteProgram(dev->prog); //glDeleteTextures(1, &dev->font_tex); glDeleteTextures(dev->texCount, dev->tex); glDeleteBuffers(1, &dev->vbo); glDeleteBuffers(1, &dev->ebo); nk_buffer_free(&dev->cmds); } static void device_draw(struct device *dev, struct nk_context *ctx, int width, int height, struct nk_vec2 scale) { const struct nk_draw_command *cmd; void *vertices, *elements; const nk_draw_index *offset = NULL; struct nk_convert_config config; static const struct nk_draw_vertex_layout_element vertex_layout[] = { {NK_VERTEX_POSITION, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_glfw_vertex, position)}, {NK_VERTEX_TEXCOORD, NK_FORMAT_FLOAT, NK_OFFSETOF(struct nk_glfw_vertex, uv)}, {NK_VERTEX_COLOR, NK_FORMAT_R8G8B8A8, NK_OFFSETOF(struct nk_glfw_vertex, col)}, {NK_VERTEX_LAYOUT_END} }; struct nk_buffer vbuf, ebuf; GLfloat ortho[4][4] = { {2.0f, 0.0f, 0.0f, 0.0f}, {0.0f,-2.0f, 0.0f, 0.0f}, {0.0f, 0.0f,-1.0f, 0.0f}, {-1.0f,1.0f, 0.0f, 1.0f}, }; ortho[0][0] /= (GLfloat)width; ortho[1][1] /= (GLfloat)height; /* setup global state */ glEnable(GL_BLEND); glBlendEquation(GL_FUNC_ADD); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); glEnable(GL_SCISSOR_TEST); glActiveTexture(GL_TEXTURE0); /* setup program */ glUseProgram(dev->prog); glUniform1i(dev->uniform_tex, 0); glUniformMatrix4fv(dev->uniform_proj, 1, GL_FALSE, &ortho[0][0]); /* allocate vertex and element buffer */ glBindVertexArray(dev->vao); glBindBuffer(GL_ARRAY_BUFFER, dev->vbo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, dev->ebo); glBufferData(GL_ARRAY_BUFFER, MAX_VERTEX_MEMORY, NULL, GL_STREAM_DRAW); glBufferData(GL_ELEMENT_ARRAY_BUFFER, MAX_ELEMENT_MEMORY, NULL, GL_STREAM_DRAW); /* load draw vertices & elements directly into vertex + element buffer */ vertices = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY); elements = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY); /* fill convert configuration */ memset(&config, 0, sizeof(config)); config.vertex_layout = vertex_layout; config.vertex_size = sizeof(struct nk_glfw_vertex); config.vertex_alignment = NK_ALIGNOF(struct nk_glfw_vertex); config.tex_null = dev->tex_null; config.circle_segment_count = 22; config.curve_segment_count = 22; config.arc_segment_count = 22; config.global_alpha = 1.0f; config.shape_AA = NK_ANTI_ALIASING_ON; config.line_AA = NK_ANTI_ALIASING_ON; /* setup buffers to load vertices and elements */ nk_buffer_init_fixed(&vbuf, vertices, MAX_VERTEX_MEMORY); nk_buffer_init_fixed(&ebuf, elements, MAX_ELEMENT_MEMORY); /* convert from command queue into draw list */ nk_convert(ctx, &dev->cmds, &vbuf, &ebuf, &config); glUnmapBuffer(GL_ARRAY_BUFFER); glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER); /* iterate over and execute each draw command */ nk_draw_foreach(cmd, ctx, &dev->cmds) { if (!cmd->elem_count) continue; glBindTexture(GL_TEXTURE_2D, (GLuint)cmd->texture.id); glScissor( (GLint)(cmd->clip_rect.x * scale.x), (GLint)((height - (GLint)(cmd->clip_rect.y + cmd->clip_rect.h)) * scale.y), (GLint)(cmd->clip_rect.w * scale.x), (GLint)(cmd->clip_rect.h * scale.y)); glDrawElements(GL_TRIANGLES, (GLsizei)cmd->elem_count, GL_UNSIGNED_SHORT, offset); offset += cmd->elem_count; } nk_clear(ctx); nk_buffer_clear(&dev->cmds); /* default OpenGL state */ glUseProgram(0); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); glBindVertexArray(0); glDisable(GL_BLEND); glDisable(GL_SCISSOR_TEST); } OpenGLRenderDevice::OpenGLRenderDevice() : dev(new device) { device_init(dev); } // virtual OpenGLRenderDevice::~OpenGLRenderDevice() { device_shutdown(dev); delete dev; } /* // virtual void OpenGLRenderDevice::Create() { device_init(dev); } // virtual void OpenGLRenderDevice::Destroy() { device_shutdown(dev); } */ nk_draw_null_texture* OpenGLRenderDevice::NullTexture() { return &dev->tex_null; } // virtual struct nk_image OpenGLRenderDevice::UploadTexture(Image& image, bool generateMips) { return device_upload_texture(dev, image.Data(), image.Width(), image.Height(), generateMips); } // virtual void OpenGLRenderDevice::Prepare(int width, int height) { glViewport(0, 0, width, height); glClear(GL_COLOR_BUFFER_BIT); glClearColor(0.3f, 0.3f, 0.3f, 1.0f); } // virtual void OpenGLRenderDevice::Draw(nk_context *ctx, int width, int height, struct nk_vec2 scale) { device_draw(dev, ctx, width, height, scale); } // virtual void OpenGLRenderDevice::Present() { } } // GameEngine namespace