From: José Fonseca <jose.r.fonseca@gmail.com>
Date: Tue, 24 May 2011 08:13:56 +0000 (+0100)
Subject: Move snapshooting to glstate.
X-Git-Url: https://git.cworth.org/git?a=commitdiff_plain;h=96404a790de7891a30bd4e3e668b436a735efde0;p=apitrace

Move snapshooting to glstate.
---

diff --git a/glretrace_main.cpp b/glretrace_main.cpp
index 1c128d7..6a740d3 100644
--- a/glretrace_main.cpp
+++ b/glretrace_main.cpp
@@ -103,31 +103,6 @@ checkGlError(Trace::Call &call) {
 }
 
 
-static void color_snapshot(Image::Image &image) {
-    GLint drawbuffer = double_buffer ? GL_BACK : GL_FRONT;
-    GLint readbuffer = double_buffer ? GL_BACK : GL_FRONT;
-    glGetIntegerv(GL_DRAW_BUFFER, &drawbuffer);
-    glGetIntegerv(GL_READ_BUFFER, &readbuffer);
-    glReadBuffer(drawbuffer);
-
-    glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
-    glPixelStorei(GL_PACK_SWAP_BYTES, GL_FALSE);
-    glPixelStorei(GL_PACK_LSB_FIRST, GL_FALSE);
-    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
-    glPixelStorei(GL_PACK_IMAGE_HEIGHT, 0);
-    glPixelStorei(GL_PACK_SKIP_ROWS, 0);
-    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
-    glPixelStorei(GL_PACK_SKIP_IMAGES, 0);
-    glPixelStorei(GL_PACK_ALIGNMENT, 1);
-
-    glReadPixels(0, 0, image.width, image.height, GL_RGBA, GL_UNSIGNED_BYTE, image.pixels);
-    
-    glPopClientAttrib();
-
-    glReadBuffer(readbuffer);
-}
-
-
 void snapshot(unsigned call_no) {
     if (!drawable ||
         (!snapshot_prefix && !compare_prefix)) {
@@ -148,21 +123,25 @@ void snapshot(unsigned call_no) {
         }
     }
 
-    Image::Image src(drawable->width, drawable->height, true);
-    color_snapshot(src);
+    Image::Image *src = glstate::getDrawBufferImage(GL_RGBA);
+    if (!src) {
+        return;
+    }
 
     if (snapshot_prefix) {
         char filename[PATH_MAX];
         snprintf(filename, sizeof filename, "%s%010u.png", snapshot_prefix, call_no);
-        if (src.writePNG(filename) && retrace::verbosity >= 0) {
+        if (src->writePNG(filename) && retrace::verbosity >= 0) {
             std::cout << "Wrote " << filename << "\n";
         }
     }
 
     if (ref) {
-        std::cout << "Snapshot " << call_no << " average precision of " << src.compare(*ref) << " bits\n";
+        std::cout << "Snapshot " << call_no << " average precision of " << src->compare(*ref) << " bits\n";
         delete ref;
     }
+
+    delete src;
 }
 
 
diff --git a/glstate.cpp b/glstate.cpp
index 8fdc75d..2fa4cb5 100644
--- a/glstate.cpp
+++ b/glstate.cpp
@@ -405,6 +405,50 @@ getDrawableBounds(GLint *width, GLint *height) {
 }
 
 
+Image::Image *
+getDrawBufferImage(GLenum format) {
+    GLint width, height;
+
+    if (format != GL_RGBA) {
+        // FIXME: this function can only handle 4-channel images
+        return NULL;
+    }
+
+    if (!getDrawableBounds(&width, &height)) {
+        return NULL;
+    }
+
+    Image::Image *image = new Image::Image(width, height, true);
+    if (!image) {
+        return NULL;
+    }
+
+    GLint drawbuffer = GL_NONE;
+    GLint readbuffer = GL_NONE;
+    glGetIntegerv(GL_DRAW_BUFFER, &drawbuffer);
+    glGetIntegerv(GL_READ_BUFFER, &readbuffer);
+    glReadBuffer(drawbuffer);
+
+    glPushClientAttrib(GL_CLIENT_PIXEL_STORE_BIT);
+    glPixelStorei(GL_PACK_SWAP_BYTES, GL_FALSE);
+    glPixelStorei(GL_PACK_LSB_FIRST, GL_FALSE);
+    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
+    glPixelStorei(GL_PACK_IMAGE_HEIGHT, 0);
+    glPixelStorei(GL_PACK_SKIP_ROWS, 0);
+    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
+    glPixelStorei(GL_PACK_SKIP_IMAGES, 0);
+    glPixelStorei(GL_PACK_ALIGNMENT, 1);
+
+    glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, image->pixels);
+
+    glPopClientAttrib();
+
+    glReadBuffer(readbuffer);
+
+    return image;
+}
+
+
 static inline void
 dumpDrawBufferImage(JSONWriter &json, GLenum format)
 {
diff --git a/glstate.hpp b/glstate.hpp
index abbfad0..2cc929a 100644
--- a/glstate.hpp
+++ b/glstate.hpp
@@ -35,6 +35,11 @@
 class JSONWriter;
 
 
+namespace Image {
+    class Image;
+}
+
+
 namespace glstate {
 
 
@@ -46,6 +51,9 @@ void dumpParameters(JSONWriter &json);
 
 void dumpCurrentContext(std::ostream &os);
 
+Image::Image *
+getDrawBufferImage(GLenum format);
+
 
 } /* namespace glstate */