Call glFramebufferTexture2D as rarely as possible

Turns out performance is absolutely abysmal on my laptop's copy of
Windows 10 (AMD A9 APU).

This is only one of the weird bottleecks: glFramebufferTexture2D
is a CPU sinkhole, so don't call it often.
This commit is contained in:
Clownacy 2019-08-09 15:55:42 +01:00
parent ac273d2d7c
commit b1a706c312

View file

@ -205,6 +205,17 @@ static GLuint CompileShader(const char *vertex_shader_source, const char *fragme
return program_id;
}
static void SetFramebufferTarget(GLuint texture_id)
{
static GLuint last_framebuffer_target;
if (texture_id != last_framebuffer_target)
{
last_framebuffer_target = texture_id;
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_id, 0);
}
}
SDL_Window* Backend_CreateWindow(const char *title, int width, int height)
{
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
@ -410,7 +421,7 @@ static void BlitCommon(Backend_Surface *source_surface, const RECT *rect, Backen
return;
// Point our framebuffer to the destination texture
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, destination_surface->texture_id, 0);
SetFramebufferTarget(destination_surface->texture_id);
glViewport(0, 0, destination_surface->width, destination_surface->height);
// Switch to colour-key shader if we have to
@ -474,7 +485,7 @@ static void ColourFillCommon(Backend_Surface *surface, const RECT *rect, unsigne
return;
// Point our framebuffer to the destination texture
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, surface->texture_id, 0);
SetFramebufferTarget(surface->texture_id);
glViewport(0, 0, surface->width, surface->height);
glUseProgram(program_colour_fill);
@ -597,7 +608,7 @@ static void DrawGlyphCommon(Backend_Surface *surface, Backend_Glyph *glyph, long
return;
// Point our framebuffer to the destination texture
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, surface->texture_id, 0);
SetFramebufferTarget(surface->texture_id);
glViewport(0, 0, surface->width, surface->height);
glEnable(GL_BLEND);