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Rewrite the texture grid positioning code again, fixing several visual defects that showed up in OpenGL 1.1 mode. Updates #1153. 

Originally committed to SVN as r4097.
This commit is contained in:
Thomas Goyne 2010-02-14 17:41:41 +00:00
parent c9ba8329ad
commit 175b2a4648
1 changed files with 84 additions and 96 deletions
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166
aegisub/src/video_out_gl.cpp
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@ -1,4 +1,4 @@
// Copyright (c) 2009, Thomas Goyne
// Copyright (c) 2010, Thomas Goyne
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
@ -53,19 +53,12 @@
#include "utils.h"
#include "video_frame.h"
// Windows only has headers for OpenGL 1.1 and GL_CLAMP_TO_EDGE is 1.2
#ifndef GL_CLAMP_TO_EDGE
#define GL_CLAMP_TO_EDGE 0x812F
#endif
#define CHECK_INIT_ERROR(cmd) cmd; if (GLenum err = glGetError()) throw VideoOutInitException(_T(#cmd), err)
#define CHECK_ERROR(cmd) cmd; if (GLenum err = glGetError()) throw VideoOutRenderException(_T(#cmd), err)
/// @brief Structure tracking all precomputable information about a subtexture
struct VideoOutGL::TextureInfo {
/// The OpenGL texture id this is for
GLuint textureID;
/// The byte offset into the frame's data block
int dataOffset;
int sourceH;
int sourceW;
@ -106,7 +99,7 @@ static bool TestTexture(int width, int height, GLint format) {
glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &format);
while (glGetError()) { } // Silently swallow all errors as we don't care why it failed if it did
wxLogDebug("VideoOutGL::TestTexture: %dx%d\n", width, height);
wxLogDebug(L"VideoOutGL::TestTexture: %dx%d\n", width, height);
return format != 0;
}
@ -138,22 +131,10 @@ void VideoOutGL::DetectOpenGLCapabilities() {
// Test for the maximum supported texture size
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
while (maxTextureSize > 64 && !TestTexture(maxTextureSize, maxTextureSize, internalFormat)) maxTextureSize >>= 1;
wxLogDebug("VideoOutGL::DetectOpenGLCapabilities: Maximum texture size is %dx%d\n", maxTextureSize, maxTextureSize);
wxLogDebug(L"VideoOutGL::DetectOpenGLCapabilities: Maximum texture size is %dx%d\n", maxTextureSize, maxTextureSize);
// Test for rectangular texture support
supportsRectangularTextures = TestTexture(maxTextureSize, maxTextureSize >> 1, internalFormat);
// Test GL_CLAMP_TO_EDGE support
glTexImage2D(GL_PROXY_TEXTURE_2D, 0, GL_RGBA8, 64, 64, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
if (glGetError()) {
supportsGlClampToEdge = false;
wxLogDebug("VideoOutGL::DetectOpenGLCapabilities: Using GL_CLAMP\n");
}
else {
supportsGlClampToEdge = true;
wxLogDebug("VideoOutGL::DetectOpenGLCapabilities: Using GL_CLAMP_TO_EDGE\n");
}
}
/// @brief If needed, create the grid of textures for displaying frames of the given format
@ -162,13 +143,13 @@ void VideoOutGL::DetectOpenGLCapabilities() {
/// @param format The frame's format
/// @param bpp The frame's bytes per pixel
void VideoOutGL::InitTextures(int width, int height, GLenum format, int bpp, bool flipped) {
frameFlipped = flipped;
// Do nothing if the frame size and format are unchanged
if (width == frameWidth && height == frameHeight && format == frameFormat && flipped == frameFlipped) return;
if (width == frameWidth && height == frameHeight && format == frameFormat) return;
frameWidth = width;
frameHeight = height;
frameFormat = format;
frameFlipped = flipped;
wxLogDebug("VideoOutGL::InitTextures: Video size: %dx%d\n", width, height);
wxLogDebug(L"VideoOutGL::InitTextures: Video size: %dx%d\n", width, height);
DetectOpenGLCapabilities();
@ -180,89 +161,88 @@ void VideoOutGL::InitTextures(int width, int height, GLenum format, int bpp, boo
}
// Create the textures
textureRows = (int)ceil(double(height) / maxTextureSize);
textureCols = (int)ceil(double(width) / maxTextureSize);
int textureArea = maxTextureSize - 2;
textureRows = (int)ceil(double(height) / textureArea);
textureCols = (int)ceil(double(width) / textureArea);
textureIdList.resize(textureRows * textureCols);
textureList.resize(textureRows * textureCols);
CHECK_INIT_ERROR(glGenTextures(textureIdList.size(), &textureIdList[0]));
/* Unfortunately, we can't simply use one of the two standard ways to do
* tiled textures to work around texture size limits in OpenGL, due to our
* need to support Microsoft's OpenGL emulation for RDP/VPC/video card
* drivers that don't support OpenGL (such as the ones which Windows
* Update pushes for ATI cards in Windows 7). GL_CLAMP_TO_EDGE requires
* OpenGL 1.2, but the emulation only supports 1.1. GL_CLAMP + borders has
* correct results, but takes several seconds to render each frame. As a
* result, the code below essentially manually reimplements borders, by
* just not using the edge when mapping the texture onto a quad. The one
* exception to this is the texture edges which are also frame edges, as
* there does not appear to be a trivial way to mirror the edges, and the
* nontrivial ways are more complex that is worth to avoid a single row of
* slightly discolored pixels along the edges at zooms over 100%.
*
* Given a 64x64 maximum texture size:
* Quads touching the top of the frame are 63 pixels tall
* Quads touching the bottom of the frame are up to 63 pixels tall
* All other quads are 62 pixels tall
* Quads not on the top skip the first row of the texture
* Quads not on the bottom skip the last row of the texture
* Width behaves in the same way with respect to left/right edges
*/
// Calculate the position information for each texture
int sourceY = 0;
float destY = -1.0f;
for (int i = 0; i < textureRows; i++) {
int sourceX = 0;
float destX = -1.0f;
int lastRow = textureRows - 1;
int lastCol = textureCols - 1;
for (int row = 0; row < textureRows; ++row) {
for (int col = 0; col < textureCols; ++col) {
TextureInfo& ti = textureList[row * textureCols + col];
int sourceH = maxTextureSize;
int textureH = maxTextureSize;
// If the last row doesn't need a full texture, shrink it to the smallest one possible
if (i == textureRows - 1 && height % maxTextureSize > 0) {
sourceH = height % maxTextureSize;
textureH = SmallestPowerOf2(sourceH);
// Width and height of the area read from the frame data
int sourceX = col * textureArea;
int sourceY = row * textureArea;
ti.sourceW = min(frameWidth - sourceX, maxTextureSize);
ti.sourceH = min(frameHeight - sourceY, maxTextureSize);
// Used instead of GL_PACK_SKIP_ROWS/GL_PACK_SKIP_PIXELS due to
// performance issues with the emulation
ti.dataOffset = sourceY * frameWidth * bpp + sourceX * bpp;
int textureHeight = SmallestPowerOf2(ti.sourceH);
int textureWidth = SmallestPowerOf2(ti.sourceW);
if (!supportsRectangularTextures) {
textureWidth = textureHeight = max(textureWidth, textureHeight);
}
for (int j = 0; j < textureCols; j++) {
TextureInfo& ti = textureList[i * textureCols + j];
// Location where this texture is placed
// X2/Y2 will be offscreen unless the video frame happens to
// exactly use all of the texture
ti.destX1 = sourceX + (col != 0);
ti.destY1 = sourceY + (row != 0);
ti.destX2 = sourceX + textureWidth - (col != lastCol);
ti.destY2 = sourceY + textureHeight - (row != lastRow);
// Copy the current position information into the struct
ti.destX1 = destX;
ti.destY1 = destY;
ti.sourceH = sourceH;
ti.textureID = textureIdList[i * textureCols + j];
// Portion of the texture actually used
ti.texTop = row == 0 ? 0 : 1.0f / textureHeight;
ti.texLeft = col == 0 ? 0 : 1.0f / textureWidth;
ti.texBottom = row == lastRow ? 1.0f : 1.0f - 1.0f / textureHeight;
ti.texRight = col == lastCol ? 1.0f : 1.0f - 1.0f / textureWidth;
ti.sourceW = maxTextureSize;
int textureW = maxTextureSize;
// If the last column doesn't need a full texture, shrink it to the smallest one possible
if (j == textureCols - 1 && width % maxTextureSize > 0) {
ti.sourceW = width % maxTextureSize;
textureW = SmallestPowerOf2(ti.sourceW);
ti.textureID = textureIdList[row * textureCols + col];
CreateTexture(textureWidth, textureHeight, ti, format);
}
int w = textureW;
int h = textureH;
if (!supportsRectangularTextures) w = h = MAX(w, h);
CreateTexture(w, h, ti, format);
if (!supportsGlClampToEdge) {
// Stretch the texture a half pixel in each direction to eliminate the border
ti.texLeft = 1.0f / (2 * w);
ti.texTop = 1.0f / (2 * h);
}
ti.destX2 = ti.destX1 + w * 2.0f / width;
ti.destY2 = ti.destY1 + h * 2.0f / height;
ti.texRight = 1.0f - ti.texLeft;
if (flipped) {
ti.texBottom = 1.0f - ti.texTop;
ti.dataOffset = sourceY * width * bpp + sourceX * bpp;
}
else {
ti.texBottom = ti.texTop - float(h - ti.sourceH) / h;
ti.texTop = 1.0f - ti.texTop - float(h - ti.sourceH) / h;
ti.dataOffset = (height - sourceY - ti.sourceH) * width * bpp + sourceX * bpp;
}
destX = ti.destX2;
sourceX += ti.sourceW;
}
destY += sourceH * 2.0f / height;
sourceY += sourceH;
}
}
void VideoOutGL::CreateTexture(int w, int h, const TextureInfo& ti, GLenum format) {
CHECK_INIT_ERROR(glBindTexture(GL_TEXTURE_2D, ti.textureID));
CHECK_INIT_ERROR(glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, w, h, 0, format, GL_UNSIGNED_BYTE, NULL));
wxLogDebug("VideoOutGL::InitTextures: Using texture size: %dx%d\n", w, h);
wxLogDebug(L"VideoOutGL::InitTextures: Using texture size: %dx%d\n", w, h);
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
GLint mode = supportsGlClampToEdge ? GL_CLAMP_TO_EDGE : GL_CLAMP;
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, mode));
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, mode));
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP));
CHECK_INIT_ERROR(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP));
}
void VideoOutGL::UploadFrameData(const AegiVideoFrame& frame) {
@ -300,6 +280,13 @@ void VideoOutGL::Render(int sw, int sh) {
CHECK_ERROR(glMatrixMode(GL_PROJECTION));
CHECK_ERROR(glLoadIdentity());
CHECK_ERROR(glPushMatrix());
if (frameFlipped) {
CHECK_ERROR(glOrtho(0.0f, frameWidth, 0.0f, frameHeight, -1000.0f, 1000.0f));
}
else {
CHECK_ERROR(glOrtho(0.0f, frameWidth, frameHeight, 0.0f, -1000.0f, 1000.0f));
}
// Render the current frame
CHECK_ERROR(glEnable(GL_TEXTURE_2D));
@ -320,6 +307,7 @@ void VideoOutGL::Render(int sw, int sh) {
}
CHECK_ERROR(glDisable(GL_TEXTURE_2D));
CHECK_ERROR(glPopMatrix());
CHECK_ERROR(glOrtho(0.0f, sw, sh, 0.0f, -1000.0f, 1000.0f));
CHECK_ERROR(glMatrixMode(GL_MODELVIEW));
CHECK_ERROR(glLoadIdentity());