From 106827c2ee1bc636384e6f99bb6574795fa08010 Mon Sep 17 00:00:00 2001 From: Clownacy Date: Wed, 31 Jul 2019 05:49:39 +0000 Subject: [PATCH] No more Legacy OpenGL ModelView matrix I'd replace it with a custom matrix, but I get the feeling the overhead of uploading a 4x4 matrix every quad is higher than just manipulating the vertexes CPU-side --- src/Backends/Rendering/OpenGL2.cpp | 92 +++++++++++++++--------------- 1 file changed, 47 insertions(+), 45 deletions(-) diff --git a/src/Backends/Rendering/OpenGL2.cpp b/src/Backends/Rendering/OpenGL2.cpp index 89eb11e6..99c2d4ee 100644 --- a/src/Backends/Rendering/OpenGL2.cpp +++ b/src/Backends/Rendering/OpenGL2.cpp @@ -46,7 +46,7 @@ static const GLchar *vertex_shader_plain = " \ #version 120\n \ void main() \ { \ - gl_Position = gl_ModelViewMatrix * gl_Vertex; \ + gl_Position = gl_Vertex; \ } \ "; @@ -55,7 +55,7 @@ static const GLchar *vertex_shader_texture = " \ void main() \ { \ gl_TexCoord[0] = gl_MultiTexCoord0; \ - gl_Position = gl_ModelViewMatrix * gl_Vertex; \ + gl_Position = gl_Vertex; \ } \ "; @@ -136,16 +136,6 @@ static GLuint CompileShader(const char *vertex_shader_source, const char *fragme return program_id; } -static void SetRenderTarget(Backend_Surface *surface) -{ - glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); - - glViewport(0, 0, surface->width, surface->height); - - glLoadIdentity(); - glOrtho(0.0, surface->width, 0.0, surface->height, 1.0, -1.0); -} - SDL_Window* Backend_CreateWindow(const char *title, int width, int height) { SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_COMPATIBILITY); @@ -319,7 +309,7 @@ void Backend_Unlock(Backend_Surface *surface) free(surface->pixels); } -static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, long x, long y, BOOL colour_key) +static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, Backend_Surface *destination_surface, long x, long y, BOOL colour_key) { if (rect->right - rect->left < 0 || rect->bottom - rect->top < 0) return; @@ -334,10 +324,10 @@ static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, long x const GLfloat texture_top = (GLfloat)rect->top / (GLfloat)source_surface->height; const GLfloat texture_bottom = (GLfloat)rect->bottom / (GLfloat)source_surface->height; - const GLfloat vertex_left = (GLfloat)x; - const GLfloat vertex_right = (GLfloat)x + (rect->right - rect->left); - const GLfloat vertex_top = (GLfloat)y; - const GLfloat vertex_bottom = (GLfloat)y + (rect->bottom - rect->top); + const GLfloat vertex_left = (x * (2.0f / destination_surface->width)) - 1.0f; + const GLfloat vertex_right = ((x + (rect->right - rect->left)) * (2.0f / destination_surface->width)) - 1.0f; + const GLfloat vertex_top = (y * (2.0f / destination_surface->height)) - 1.0f; + const GLfloat vertex_bottom = ((y + (rect->bottom - rect->top)) * (2.0f / destination_surface->height)) - 1.0f; texture_coordinate_buffer[0][0] = texture_left; texture_coordinate_buffer[0][1] = texture_top; @@ -366,9 +356,10 @@ void Backend_Blit(Backend_Surface *source_surface, const RECT *rect, Backend_Sur return; // Point our framebuffer to the destination texture - SetRenderTarget(destination_surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, destination_surface->texture_id, 0); + glViewport(0, 0, destination_surface->width, destination_surface->height); - BlitCommon(source_surface, rect, x, y, colour_key); + BlitCommon(source_surface, rect, destination_surface, x, y, colour_key); } void Backend_BlitToScreen(Backend_Surface *source_surface, const RECT *rect, long x, long y, BOOL colour_key) @@ -377,12 +368,13 @@ void Backend_BlitToScreen(Backend_Surface *source_surface, const RECT *rect, lon return; // Point our framebuffer to the screen texture - SetRenderTarget(&framebuffer_surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0); + glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height); - BlitCommon(source_surface, rect, x, y, colour_key); + BlitCommon(source_surface, rect, &framebuffer_surface, x, y, colour_key); } -static void ColourFillCommon(const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) +static void ColourFillCommon(Backend_Surface *surface, const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) { if (rect->right - rect->left < 0 || rect->bottom - rect->top < 0) return; @@ -391,14 +383,19 @@ static void ColourFillCommon(const RECT *rect, unsigned char red, unsigned char glUniform4f(uniform_colour_fill_colour, red / 255.0f, green / 255.0f, blue / 255.0f, 1.0f); - vertex_buffer[0][0] = (GLfloat)rect->left; - vertex_buffer[0][1] = (GLfloat)rect->top; - vertex_buffer[1][0] = (GLfloat)rect->right; - vertex_buffer[1][1] = (GLfloat)rect->top; - vertex_buffer[2][0] = (GLfloat)rect->right; - vertex_buffer[2][1] = (GLfloat)rect->bottom; - vertex_buffer[3][0] = (GLfloat)rect->left; - vertex_buffer[3][1] = (GLfloat)rect->bottom; + const GLfloat vertex_left = (rect->left * (2.0f / surface->width)) - 1.0f; + const GLfloat vertex_right = (rect->right * (2.0f / surface->width)) - 1.0f; + const GLfloat vertex_top = (rect->top * (2.0f / surface->height)) - 1.0f; + const GLfloat vertex_bottom = (rect->bottom * (2.0f / surface->height)) - 1.0f; + + vertex_buffer[0][0] = vertex_left; + vertex_buffer[0][1] = vertex_top; + vertex_buffer[1][0] = vertex_right; + vertex_buffer[1][1] = vertex_top; + vertex_buffer[2][0] = vertex_right; + vertex_buffer[2][1] = vertex_bottom; + vertex_buffer[3][0] = vertex_left; + vertex_buffer[3][1] = vertex_bottom; glDrawArrays(GL_TRIANGLE_FAN, 0, 4); } @@ -409,17 +406,19 @@ void Backend_ColourFill(Backend_Surface *surface, const RECT *rect, unsigned cha return; // Point our framebuffer to the destination texture - SetRenderTarget(surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); + glViewport(0, 0, surface->width, surface->height); - ColourFillCommon(rect, red, green, blue); + ColourFillCommon(surface, rect, red, green, blue); } void Backend_ColourFillToScreen(const RECT *rect, unsigned char red, unsigned char green, unsigned char blue) { // Point our framebuffer to the screen texture - SetRenderTarget(&framebuffer_surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0); + glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height); - ColourFillCommon(rect, red, green, blue); + ColourFillCommon(&framebuffer_surface, rect, red, green, blue); } void Backend_ScreenToSurface(Backend_Surface *surface, const RECT *rect) @@ -428,9 +427,10 @@ void Backend_ScreenToSurface(Backend_Surface *surface, const RECT *rect) return; // Point our framebuffer to the destination texture - SetRenderTarget(surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); + glViewport(0, 0, surface->width, surface->height); - BlitCommon(&framebuffer_surface, rect, rect->left, rect->top, FALSE); + BlitCommon(&framebuffer_surface, rect, surface, rect->left, rect->top, FALSE); } BOOL Backend_SupportsSubpixelGlyph(void) @@ -513,16 +513,16 @@ void Backend_UnloadGlyph(Backend_Glyph *glyph) free(glyph); } -static void DrawGlyphCommon(Backend_Glyph *glyph, long x, long y, const unsigned char *colours) +static void DrawGlyphCommon(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours) { glUseProgram(program_glyph); glBindTexture(GL_TEXTURE_2D, glyph->texture_id); - const GLfloat vertex_left = (GLfloat)x; - const GLfloat vertex_right = (GLfloat)x + glyph->width; - const GLfloat vertex_top = (GLfloat)y; - const GLfloat vertex_bottom = (GLfloat)y + glyph->height; + const GLfloat vertex_left = (x * (2.0f / surface->width)) - 1.0f; + const GLfloat vertex_right = ((x + glyph->width) * (2.0f / surface->width)) - 1.0f; + const GLfloat vertex_top = (y * (2.0f / surface->height)) - 1.0f; + const GLfloat vertex_bottom = ((y + glyph->height) * (2.0f / surface->height)) - 1.0f; glUniform4f(uniform_glyph_colour, colours[0] / 255.0f, colours[1] / 255.0f, colours[2] / 255.0f, 1.0f); @@ -553,9 +553,10 @@ void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, l return; // Point our framebuffer to the destination texture - SetRenderTarget(surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface->texture_id, 0); + glViewport(0, 0, surface->width, surface->height); - DrawGlyphCommon(glyph, x, y, colours); + DrawGlyphCommon(surface, glyph, x, y, colours); } void Backend_DrawGlyphToScreen(Backend_Glyph *glyph, long x, long y, const unsigned char *colours) @@ -564,9 +565,10 @@ void Backend_DrawGlyphToScreen(Backend_Glyph *glyph, long x, long y, const unsig return; // Point our framebuffer to the screen texture - SetRenderTarget(&framebuffer_surface); + glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, framebuffer_surface.texture_id, 0); + glViewport(0, 0, framebuffer_surface.width, framebuffer_surface.height); - DrawGlyphCommon(glyph, x, y, colours); + DrawGlyphCommon(&framebuffer_surface, glyph, x, y, colours); } void Backend_HandleDeviceLoss(void)