diff --git a/CMakeLists.txt b/CMakeLists.txt index 337312eb..1cb934a5 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -246,7 +246,9 @@ if(NONPORTABLE) target_compile_definitions(CSE2 PRIVATE NONPORTABLE) endif() -if(RENDERER MATCHES "Texture") +if(RENDERER MATCHES "OpenGL2") + target_sources(CSE2 PRIVATE "src/Backends/Rendering/OpenGL2.cpp") +elseif(RENDERER MATCHES "Texture") target_sources(CSE2 PRIVATE "src/Backends/Rendering/SDLTexture.cpp") elseif(RENDERER MATCHES "Surface") target_sources(CSE2 PRIVATE "src/Backends/Rendering/SDLSurface.cpp") @@ -402,6 +404,11 @@ else() target_link_libraries(CSE2 freetype) endif() +find_package(GLEW REQUIRED) +target_link_libraries(CSE2 GLEW::GLEW) +find_package(OpenGL REQUIRED) +target_link_libraries(CSE2 OpenGL::GL OpenGL::GLU) + ## # DoConfig diff --git a/src/Backends/Rendering/OpenGL2.cpp b/src/Backends/Rendering/OpenGL2.cpp new file mode 100644 index 00000000..c77688be --- /dev/null +++ b/src/Backends/Rendering/OpenGL2.cpp @@ -0,0 +1,322 @@ +#include "../Rendering.h" + +#include +#include + +#include +#include "SDL.h" + +#include "../../WindowsWrapper.h" + +#include "../../Font.h" + +typedef struct Backend_Surface +{ + GLuint texture_id; + unsigned int width; + unsigned int height; + unsigned char *pixels; +} Backend_Surface; + +static SDL_Window *window; +static SDL_GLContext context; +static GLuint colour_key_program_id; +static GLuint framebuffer_id; + +static Backend_Surface framebuffer_surface; + +static const GLchar *fragment_shader_source = " \ +#version 120\n \ +uniform sampler2D tex; \ +void main() \ +{ \ + vec4 colour = gl_Color * texture2D(tex, gl_TexCoord[0].st); \ +\ + if (colour.xyz == vec3(0.0f, 0.0f, 0.0f)) \ + discard; \ +\ + gl_FragColor = colour; \ +} \ +"; + +static GLuint CompileShader(const char *fragment_shader_source) +{ + GLint shader_status; + + GLuint program_id = glCreateProgram(); + + GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL); + glCompileShader(fragment_shader); + + glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &shader_status); + if (shader_status != GL_TRUE) + return 0; + + glAttachShader(program_id, fragment_shader); + + glLinkProgram(program_id); + + glGetProgramiv(program_id, GL_LINK_STATUS, &shader_status); + if (shader_status != GL_TRUE) + return 0; + + return program_id; +} + +BOOL Backend_Init(SDL_Window *p_window) +{ + window = p_window; + + int screen_width, screen_height; + SDL_GetWindowSize(window, &screen_width, &screen_height); + + context = SDL_GL_CreateContext(window); + + if (glewInit() != GLEW_OK) + return FALSE; + + // Check for framebuffer object extension (is part of the core spec in OpenGL 3.0, but not 2.1) + if (!GLEW_EXT_framebuffer_object) + return FALSE; + +// glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); + glOrtho(0.0, screen_width, 0.0, screen_height, 1.0, -1.0); + +// glMatrixMode(GL_PROJECTION); +// glLoadIdentity(); + + glEnable(GL_TEXTURE_2D); + + glClearColor(0.0f, 0.0f, 0.0f, 1.0f); + glClear(GL_COLOR_BUFFER_BIT); + + // Set up blank default texture (it seems to be black by default, which sucks for colour modulation) + const unsigned char white_pixel[3] = {0xFF, 0xFF, 0xFF}; + glBindTexture(GL_TEXTURE_2D, 0); + glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, 1, 1, 0, GL_RGB, GL_UNSIGNED_BYTE, white_pixel); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + + // Set up our colour-key-enabled fragment shader + colour_key_program_id = CompileShader(fragment_shader_source); + + // Set up framebuffer (used for surface-to-surface blitting) + glGenFramebuffersEXT(1, &framebuffer_id); + + // Set up framebuffer screen texture (used for screen-to-surface blitting) + glGenTextures(1, &framebuffer_surface.texture_id); + glBindTexture(GL_TEXTURE_2D, framebuffer_surface.texture_id); + glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, screen_width, screen_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + + framebuffer_surface.width = screen_width; + framebuffer_surface.height = screen_height; + + return TRUE; +} + +void Backend_Deinit(void) +{ + glDeleteTextures(1, &framebuffer_surface.texture_id); + glDeleteFramebuffersEXT(1, &framebuffer_id); + glDeleteProgram(colour_key_program_id); + SDL_GL_DeleteContext(context); +} + +void Backend_DrawScreen(void) +{ + // Disable colour-keying + glUseProgram(0); + + // Target actual screen, and not our framebuffer + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); + + // Draw framebuffer to screen + glPushMatrix(); + glLoadIdentity(); + + glBindTexture(GL_TEXTURE_2D, framebuffer_surface.texture_id); + + glBegin(GL_QUADS); + glColor3f(1.0f, 1.0f, 1.0f); + glTexCoord2f(0.0f, 1.0f); + glVertex2f(-1.0f, -1.0f); + glTexCoord2f(1.0f, 1.0f); + glVertex2f(1.0f, -1.0f); + glTexCoord2f(1.0f, 0.0f); + glVertex2f(1.0f, 1.0f); + glTexCoord2f(0.0f, 0.0f); + glVertex2f(-1.0f, 1.0f); + glEnd(); + + glPopMatrix(); + + SDL_GL_SwapWindow(window); + + // According to https://www.khronos.org/opengl/wiki/Common_Mistakes#Swap_Buffers + // the buffer should always be cleared + glClear(GL_COLOR_BUFFER_BIT); + + // Switch back to our framebuffer + glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, framebuffer_id); +} + +Backend_Surface* Backend_CreateSurface(unsigned int width, unsigned int height) +{ + Backend_Surface *surface = (Backend_Surface*)malloc(sizeof(Backend_Surface)); + + if (surface == NULL) + return NULL; + + glGenTextures(1, &surface->texture_id); + glBindTexture(GL_TEXTURE_2D, surface->texture_id); + glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + + surface->width = width; + surface->height = height; + + return surface; +} + +void Backend_FreeSurface(Backend_Surface *surface) +{ + glDeleteTextures(1, &surface->texture_id); + free(surface); +} + +unsigned char* Backend_Lock(Backend_Surface *surface, unsigned int *pitch) +{ + surface->pixels = (unsigned char*)malloc(surface->width * surface->height * 3); + *pitch = surface->width * 3; + return surface->pixels; +} + +void Backend_Unlock(Backend_Surface *surface) +{ + glBindTexture(GL_TEXTURE_2D, surface->texture_id); + glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, surface->width, surface->height, GL_RGB, GL_UNSIGNED_BYTE, surface->pixels); + free(surface->pixels); +} + +static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, long x, long y, BOOL colour_key) +{ + // Switch to colour-key shader if we have to + glUseProgram(colour_key ? colour_key_program_id : 0); + + glBindTexture(GL_TEXTURE_2D, source_surface->texture_id); + + glBegin(GL_QUADS); + glColor3f(1.0f, 1.0f, 1.0f); + glTexCoord2f((GLfloat)rect->left / (GLfloat)source_surface->width, (GLfloat)rect->top / (GLfloat)source_surface->height); + glVertex2f((GLfloat)x, (GLfloat)y); + glTexCoord2f((GLfloat)rect->right / (GLfloat)source_surface->width, (GLfloat)rect->top / (GLfloat)source_surface->height); + glVertex2f((GLfloat)x + (rect->right - rect->left), (GLfloat)y); + glTexCoord2f((GLfloat)rect->right / (GLfloat)source_surface->width, (GLfloat)rect->bottom / (GLfloat)source_surface->height); + glVertex2f((GLfloat)x + (rect->right - rect->left), (GLfloat)y + (rect->bottom - rect->top)); + glTexCoord2f((GLfloat)rect->left / (GLfloat)source_surface->width, (GLfloat)rect->bottom / (GLfloat)source_surface->height); + glVertex2f((GLfloat)x, (GLfloat)y + (rect->bottom - rect->top)); + glEnd(); +} + +void Backend_Blit(Backend_Surface *source_surface, const RECT *rect, Backend_Surface *destination_surface, long x, long y, BOOL colour_key) +{ + // Point our framebuffer to the destination texture + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, destination_surface->texture_id, 0); + + // The matrix needs resetting to fit the dimensions of the destination texture + glPushMatrix(); + glLoadIdentity(); + glOrtho(0.0, destination_surface->width, 0.0, destination_surface->height, 1.0, -1.0); + + BlitCommon(source_surface, rect, x, y, colour_key); + + glPopMatrix(); +} + +void Backend_BlitToScreen(Backend_Surface *source_surface, const RECT *rect, long x, long y, BOOL colour_key) +{ + // Point our framebuffer to the screen texture + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0); + + BlitCommon(source_surface, rect, x, y, colour_key); +} + +static void ColourFillCommon(const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) +{ + // Disable colour-keying + glUseProgram(0); + + // Use blank default texture, for a solid colour-fill + glBindTexture(GL_TEXTURE_2D, 0); + + glBegin(GL_QUADS); + glColor3f(red / 255.0f, green / 255.0f, blue / 255.0f); + glVertex2f((GLfloat)rect->left, (GLfloat)rect->top); + glVertex2f((GLfloat)rect->right, (GLfloat)rect->top); + glVertex2f((GLfloat)rect->right, (GLfloat)rect->bottom); + glVertex2f((GLfloat)rect->left, (GLfloat)rect->bottom); + glEnd(); +} + +void Backend_ColourFill(Backend_Surface *surface, const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) +{ + // Point our framebuffer to the destination texture + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); + + // The matrix needs resetting to fit the dimensions of the destination texture + glPushMatrix(); + glLoadIdentity(); + glOrtho(0.0, surface->width, 0.0, surface->height, 1.0, -1.0); + + ColourFillCommon(rect, red, green, blue); + + glPopMatrix(); +} + +void Backend_ColourFillToScreen(const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) +{ + // Point our framebuffer to the screen texture + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0); + + ColourFillCommon(rect, red, green, blue); +} + +void Backend_ScreenToSurface(Backend_Surface *surface, const RECT *rect) +{ + // Point our framebuffer to the destination texture + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); + + // The matrix needs resetting to fit the dimensions of the destination texture + glPushMatrix(); + glLoadIdentity(); + glOrtho(0.0, surface->width, 0.0, surface->height, 1.0, -1.0); + + BlitCommon(&framebuffer_surface, rect, rect->left, rect->top, FALSE); + + glPopMatrix(); +} + +void Backend_DrawText(Backend_Surface *surface, FontObject *font, int x, int y, const char *text, unsigned long colour) +{ + // Soon +} + +void Backend_DrawTextToScreen(FontObject *font, int x, int y, const char *text, unsigned long colour) +{ + // Soon +} + +void Backend_HandleDeviceLoss(void) +{ + // No problem for us +} + +void Backend_HandleWindowResize(void) +{ + // No problem for us +} diff --git a/src/Main.cpp b/src/Main.cpp index b785164f..9d8fb8f4 100644 --- a/src/Main.cpp +++ b/src/Main.cpp @@ -256,8 +256,12 @@ int main(int argc, char *argv[]) windowHeight = WINDOW_HEIGHT * 2; } + SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY); + SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2); + SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1); + // Create window - gWindow = SDL_CreateWindow(lpWindowName, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, windowWidth, windowHeight, 0); + gWindow = SDL_CreateWindow(lpWindowName, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, windowWidth, windowHeight, SDL_WINDOW_OPENGL); if (gWindow) {