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Some graphics stacks just suck (like AMD + Mesa), so we have to clear the frame buffer on each frame, otherwise garbage and/or flickering appears on undrawn areas. Fixes #53.
134 lines
3.6 KiB
C
134 lines
3.6 KiB
C
//
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// vi/render.c: Rendering functions.
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//
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// CEN64: Cycle-Accurate Nintendo 64 Emulator.
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// Copyright (C) 2015, Tyler J. Stachecki.
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//
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// This file is subject to the terms and conditions defined in
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// 'LICENSE', which is part of this source code package.
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//
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#include "common.h"
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#include "os/gl_window.h"
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#include "os/main.h"
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// Initializes OpenGL to an default state.
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void gl_window_init(struct vi_controller *vi) {
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glDisable(GL_DEPTH_TEST);
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glDisable(GL_LIGHTING);
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glDisable(GL_BLEND);
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glDisable(GL_DITHER);
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glEnable(GL_TEXTURE_2D);
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// Initialize gamma boost blend function.
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glBlendFunc(GL_ONE, GL_ONE);
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// Initialize the texture that we'll use for drawing the screen.
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
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// Initialize vertex arrays for drawing.
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glEnableClientState(GL_VERTEX_ARRAY);
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glEnableClientState(GL_TEXTURE_COORD_ARRAY);
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glTexCoordPointer(2, GL_FLOAT, 0, vi->viuv);
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glVertexPointer(2, GL_FLOAT, 0, vi->quad);
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vi->quad[0] = vi->quad[5] =
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vi->quad[6] = vi->quad[7] = -1;
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vi->quad[1] = vi->quad[2] =
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vi->quad[3] = vi->quad[4] = 1;
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vi->viuv[2] = vi->viuv[4] =
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vi->viuv[5] = vi->viuv[7] = 1;
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// Tell OpenGL that the byte order is swapped.
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glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_TRUE);
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}
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// Renders a frame.
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void gl_window_render_frame(struct vi_controller *vi, const uint8_t *buffer,
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unsigned hres, unsigned vres, unsigned hskip, unsigned type) {
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float aspect;
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glClear(GL_COLOR_BUFFER_BIT);
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switch(type) {
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case 0:
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return;
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case 1:
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assert(0 && "Attempted to use reserved frame type.");
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return;
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case 2:
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, hres + hskip, vres,
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0, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, buffer);
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break;
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case 3:
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, hres + hskip, vres,
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0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
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break;
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}
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// AA Mode 3 (Replicate<74>Pixels &<26>No<4E>Interpolation)
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if ((vi->regs[VI_STATUS_REG] & 0x300) == 0x300) {
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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}
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// AA Mode 0..2 (Antialias & Resample)
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else {
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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}
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aspect = (float) hres / (hres + hskip);
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vi->viuv[2] = vi->viuv[4] = aspect;
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glDrawArrays(GL_QUADS, 0, 4);
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// Gamma boost blend.
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if (vi->regs[VI_STATUS_REG] & 0x8) {
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glEnable(GL_BLEND);
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glColor3f(0.15f, 0.15f, 0.15f);
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glDrawArrays(GL_QUADS, 0, 4); // Texture quad blend
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glDisable(GL_TEXTURE_2D);
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glColor3f(0.1f, 0.1f, 0.1f);
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glDrawArrays(GL_QUADS, 0, 4); // White quad blend
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glDisable(GL_BLEND);
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glEnable(GL_TEXTURE_2D);
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glColor3f(1.0f, 1.0f, 1.0f);
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}
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cen64_gl_window_swap_buffers(vi->window);
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}
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// Called when the window was resized.
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void gl_window_resize_cb(int width, int height) {
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float aspect = 640.0 / 474.0;
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if (height <= 0)
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height = 1;
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glViewport(0, 0, width, height);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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if((float) width / (float) height > aspect) {
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aspect = 474.0 / 640.0;
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aspect *= (float)width / (float)height;
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glOrtho(-aspect, aspect, -1, 1, -1, 1);
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}
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else {
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aspect *= (float)height / (float)width;
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glOrtho(-1, 1, -aspect, aspect, -1, 1);
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}
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glClear(GL_COLOR_BUFFER_BIT);
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}
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