Re-enable data collection, using a temporary

offscreen GL context this time.
Review URL: http://codereview.chromium.org/3212001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57764 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 68 insertions, 50 deletions

diff --git a/chrome/gpu/gpu_info_collector_mac.mm b/chrome/gpu/gpu_info_collector_mac.mm
index 0b494d3..097a840 100644
--- a/chrome/gpu/gpu_info_collector_mac.mm
+++ b/chrome/gpu/gpu_info_collector_mac.mm
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include "chrome/gpu/gpu_info_collector.h"
+#include "base/string_piece.h"
 #include "base/sys_string_conversions.h"
+#include "app/gfx/gl/gl_context.h"
 
 #import <Cocoa/Cocoa.h>
 #import <Foundation/Foundation.h>
@@ -55,8 +57,6 @@ static void CollectVideoCardInfo(CGDirectDisplayID displayID,
   CFReleaseIf(deviceIDRef);
 }
 
-// TODO(maf): uncomment when using code below is re-enabled.
-/*
 // Return a pointer to the last character with value c in string s.
 // Returns NULL if c is not found.
 static char* FindLastChar(char *s, char c) {
@@ -69,72 +69,90 @@ static char* FindLastChar(char *s, char c) {
   }
   return s_found;
 }
-*/
 
+// Gets the numeric HLSL version.
+// You pass it the current GL major version, to give it a hint where to look.
+static int GetShaderNumericVersion(int gl_major_version) {
+  int gl_hlsl_major = 0, gl_hlsl_minor = 0;
+  int shader_version = 0;
 
-bool CollectGraphicsInfo(GPUInfo& gpu_info) {
-  int vendor_id = 0;
-  int device_id = 0;
-  std::wstring driver_version = L"";
-  uint32 pixel_shader_version = 0u;
-  uint32 vertex_shader_version = 0u;
-  uint32 gl_version = 0u;
+  if (gl_major_version == 1) {
+    char *gl_extensions_string = (char*)glGetString(GL_EXTENSIONS);
+    if (strstr(gl_extensions_string, "GL_ARB_shading_language_100")) {
+      gl_hlsl_major = 1;
+      gl_hlsl_minor = 0;
+    }
+  } else if (gl_major_version > 1) {
+    char *glsl_version_string = (char*)glGetString(GL_SHADING_LANGUAGE_VERSION);
+    if (glsl_version_string)
+      sscanf(glsl_version_string, "%u.%u", &gl_hlsl_major, &gl_hlsl_minor);
+  }
+
+  shader_version = (gl_hlsl_major << 8) | (gl_hlsl_minor & 0xFF);
+  return shader_version;
+}
 
-  CollectVideoCardInfo(kCGDirectMainDisplay, &vendor_id, &device_id);
 
-  // TODO(maf): when this is called, there is no OpenGL context
-  // current, so calls to glGetString crash.
-  /*
-  char *gl_version_string = (char*)glGetString(GL_VERSION);
-  char *gl_extensions_string = (char*)glGetString(GL_EXTENSIONS);
+static std::wstring CStringToWString(const char *s) {
+  base::StringPiece sp(s);
+  return base::SysUTF8ToWide(sp);
+}
 
-  if ((gl_version_string == NULL) || (gl_extensions_string == NULL))
-    return false;
 
-  // Get the OpenGL version from the start of the string.
+// Returns the driver version string as its value, and also returns the
+// gl version and shader language version by setting the arguments pointed to.
+static std::wstring CollectGLInfo(int *out_gl_version,
+                                  int *out_shader_version) {
   int gl_major = 0, gl_minor = 0;
+  char *gl_version_string = NULL;
+  std::wstring driver_version;
+
+  gl_version_string = (char*)glGetString(GL_VERSION);
   sscanf(gl_version_string, "%u.%u",  &gl_major, &gl_minor);
 
-  // Get the OpenGL driver version.
+  *out_gl_version = (gl_major << 8) | (gl_minor & 0xFF);
+  *out_shader_version = GetShaderNumericVersion(gl_major);
+
+  // Extract the OpenGL driver version string from the GL_VERSION string.
   // Mac OpenGL drivers have the driver version
   // at the end of the gl version string preceded by a dash.
+  // Use some jiggery-pokery to turn that utf8 string into a std::wstring.
   char *s = FindLastChar(gl_version_string, '-');
-  if (s) {
-    NSString *driver_version_ns = [[NSString alloc ] initWithUTF8String:s + 1];
-    driver_version = base::SysNSStringToWide(driver_version_ns);
-    [driver_version_ns release];
-  }
+  if (s)
+    driver_version = CStringToWString(s + 1);
 
-  // Get the HLSL version.
-  // On OpenGL 1.x it's 1.0 if the GL_ARB_shading_language_100 extension is
-  // present.
-  // On OpenGL 2.x  it's a matter of getting the GL_SHADING_LANGUAGE_VERSION
-  // string.
-  int gl_hlsl_major = 0, gl_hlsl_minor = 0;
-  if ((gl_major == 1) &&
-      strstr(gl_extensions_string, "GL_ARB_shading_language_100")) {
-    gl_hlsl_major = 1;
-    gl_hlsl_minor = 0;
-  } else if (gl_major >= 2) {
-    char* glsl_version_string = (char*)glGetString(GL_SHADING_LANGUAGE_VERSION);
-    if (glsl_version_string) {
-      sscanf(glsl_version_string, "%u.%u", &gl_hlsl_major, &gl_hlsl_minor);
+  return driver_version;
+}
+
+
+bool CollectGraphicsInfo(GPUInfo& gpu_info) {
+  // Video Card data.
+  int vendor_id = 0, device_id = 0;
+  // OpenGL data.
+  std::wstring driver_version = L"";
+  int gl_version = 0, shader_version = 0;
+
+  CollectVideoCardInfo(kCGDirectMainDisplay, &vendor_id, &device_id);
+
+  // Temporarily make an offscreen GL context so we can gather info from it.
+  if (gfx::GLContext::InitializeOneOff()) {
+    gfx::GLContext* ctx = gfx::GLContext::CreateOffscreenGLContext(NULL);
+    if (ctx) {
+      if (ctx->MakeCurrent()) {
+        driver_version = CollectGLInfo(&gl_version, &shader_version);
+      }
+      ctx->Destroy();
     }
   }
-  pixel_shader_version = ((gl_hlsl_major << 16) & 0xffff0000)
-                         + (gl_hlsl_minor & 0x0000ffff);
-
-  // OpenGL doesn't have separate versions for pixel and vertex shader
-  // languages, so set them both to the GL_SHADING_LANGUAGE_VERSION value.
-  vertex_shader_version = pixel_shader_version;
 
-  gl_version = ((gl_major << 16) & 0xffff0000)
-               + (gl_minor & 0x0000ffff);
-  */
 
-  gpu_info.SetGraphicsInfo(vendor_id, device_id, driver_version,
-                           pixel_shader_version, vertex_shader_version,
+  // OpenGL doesn't have separate versions for pixel and vertex shader
+  // languages, so we just pass the shader_version for both.
+  gpu_info.SetGraphicsInfo(vendor_id, device_id,
+                           driver_version,
+                           shader_version, shader_version,
                            gl_version);
+
   return true;
 }