Simplify and centralize multisample counts.

Change-Id: I012bb669444e28f844c5571ff639b31dd1a35e1d
Reviewed-on: https://swiftshader-review.googlesource.com/3950
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>

src/OpenGL/libGLESv2/Context.cpp

diff --git a/src/OpenGL/libGLESv2/Context.cpp b/src/OpenGL/libGLESv2/Context.cpp
index 2d1c16b..72aa86f 100644
--- a/src/OpenGL/libGLESv2/Context.cpp
+++ b/src/OpenGL/libGLESv2/Context.cpp
@@ -3843,19 +3843,21 @@
     return GL_NO_ERROR;

 }

 

-int Context::getSupportedMultiSampleDepth(sw::Format format, int requested)

+int Context::getSupportedMultisampleCount(int requested)

 {

-    if(requested <= 0)

-    {

-        return 0;

-    }

-	

-	if(requested <= 2)

+	int supported = 0;

+

+	for(int i = NUM_MULTISAMPLE_COUNTS - 1; i >= 0; i--)

 	{

-		return requested;

+		if(supported >= requested)

+		{

+			return supported;

+		}

+

+		supported = multisampleCount[i];

 	}

-	

-	return 4;

+

+	return supported;

 }

 

 void Context::detachBuffer(GLuint buffer)

src/OpenGL/libGLESv2/Context.h

diff --git a/src/OpenGL/libGLESv2/Context.h b/src/OpenGL/libGLESv2/Context.h
index ef7769b..da624be 100644
--- a/src/OpenGL/libGLESv2/Context.h
+++ b/src/OpenGL/libGLESv2/Context.h
@@ -142,6 +142,10 @@
 

 const GLint NUM_COMPRESSED_TEXTURE_FORMATS = sizeof(compressedTextureFormats) / sizeof(compressedTextureFormats[0]);

 

+const GLint multisampleCount[] = {4, 2, 1};

+const GLint NUM_MULTISAMPLE_COUNTS = sizeof(multisampleCount) / sizeof(multisampleCount[0]);

+const GLint IMPLEMENTATION_MAX_SAMPLES = multisampleCount[0];

+

 const float ALIASED_LINE_WIDTH_RANGE_MIN = 1.0f;

 const float ALIASED_LINE_WIDTH_RANGE_MAX = 1.0f;

 const float ALIASED_POINT_SIZE_RANGE_MIN = 0.125f;

@@ -651,7 +655,7 @@
 

     GLenum getError();

 

-    static int getSupportedMultiSampleDepth(sw::Format format, int requested);

+    static int getSupportedMultisampleCount(int requested);

     

     void blitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, 

                          GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,

src/OpenGL/libGLESv2/Renderbuffer.cpp

diff --git a/src/OpenGL/libGLESv2/Renderbuffer.cpp b/src/OpenGL/libGLESv2/Renderbuffer.cpp
index 9923956..2f641f6 100644
--- a/src/OpenGL/libGLESv2/Renderbuffer.cpp
+++ b/src/OpenGL/libGLESv2/Renderbuffer.cpp
@@ -442,12 +442,12 @@
 	}
 }
 
-Colorbuffer::Colorbuffer(int width, int height, GLenum format, GLsizei samples) : mRenderTarget(NULL)
+Colorbuffer::Colorbuffer(int width, int height, GLenum format, GLsizei samples) : mRenderTarget(nullptr)
 {
 	Device *device = getDevice();
 
 	sw::Format requestedFormat = es2sw::ConvertRenderbufferFormat(format);
-	int supportedSamples = Context::getSupportedMultiSampleDepth(requestedFormat, samples);
+	int supportedSamples = Context::getSupportedMultisampleCount(samples);
 
 	if(width > 0 && height > 0)
 	{
@@ -519,13 +519,11 @@
 	}
 }
 
-DepthStencilbuffer::DepthStencilbuffer(int width, int height, GLsizei samples)
+DepthStencilbuffer::DepthStencilbuffer(int width, int height, GLsizei samples) : mDepthStencil(nullptr)
 {
 	Device *device = getDevice();
 
-	mDepthStencil = NULL;
-	
-	int supportedSamples = Context::getSupportedMultiSampleDepth(sw::FORMAT_D24S8, samples);
+	int supportedSamples = Context::getSupportedMultisampleCount(samples);
 
 	if(width > 0 && height > 0)
 	{

src/OpenGL/libGLESv2/Texture.h

diff --git a/src/OpenGL/libGLESv2/Texture.h b/src/OpenGL/libGLESv2/Texture.h
index 33123b8..7f0519a 100644
--- a/src/OpenGL/libGLESv2/Texture.h
+++ b/src/OpenGL/libGLESv2/Texture.h
@@ -42,7 +42,6 @@
     IMPLEMENTATION_MAX_TEXTURE_SIZE = 1 << (MIPMAP_LEVELS - 1),

     IMPLEMENTATION_MAX_CUBE_MAP_TEXTURE_SIZE = 1 << (MIPMAP_LEVELS - 1),

 	IMPLEMENTATION_MAX_RENDERBUFFER_SIZE = OUTLINE_RESOLUTION,

-	IMPLEMENTATION_MAX_SAMPLES = 4,

 	IMPLEMENTATION_MAX_COLOR_ATTACHMENTS = MAX_COLOR_ATTACHMENTS,

 	IMPLEMENTATION_MAX_DRAW_BUFFERS = 8,

 	IMPLEMENTATION_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS = MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS,

src/OpenGL/libGLESv2/libGLESv3.cpp

diff --git a/src/OpenGL/libGLESv2/libGLESv3.cpp b/src/OpenGL/libGLESv2/libGLESv3.cpp
index 0d3bccf..2e22678 100644
--- a/src/OpenGL/libGLESv2/libGLESv3.cpp
+++ b/src/OpenGL/libGLESv2/libGLESv3.cpp
@@ -3968,35 +3968,15 @@
 		return error(GL_INVALID_ENUM);

 	}

 

-	sw::Format requestedFormat = es2sw::ConvertRenderbufferFormat(internalformat);

-	std::vector<GLint> supportedMultiSampleDepths;

-	int maxDepth = Context::getSupportedMultiSampleDepth(requestedFormat, INT_MAX);

-	for(int depth = maxDepth; depth > 1;)

-	{

-		supportedMultiSampleDepths.push_back(depth);

-		for(int nextDepth = depth - 1; nextDepth >= 0; --nextDepth)

-		{

-			int supportedDepth = Context::getSupportedMultiSampleDepth(requestedFormat, nextDepth);

-			if(supportedDepth != depth)

-			{

-				depth = supportedDepth;

-				break;

-			}

-		}

-	}

-

 	switch(pname)

 	{

 	case GL_NUM_SAMPLE_COUNTS:

-		*params = supportedMultiSampleDepths.size();

+		*params = NUM_MULTISAMPLE_COUNTS;

 		break;

 	case GL_SAMPLES:

+		for(int i = 0; i < NUM_MULTISAMPLE_COUNTS && i < bufSize; i++)

 		{

-			size_t returnCount = std::min<size_t>(bufSize, supportedMultiSampleDepths.size());

-			for(size_t sampleIndex = 0; sampleIndex < returnCount; ++sampleIndex)

-			{

-				params[sampleIndex] = supportedMultiSampleDepths[sampleIndex];

-			}

+			params[i] = multisampleCount[i];

 		}

 		break;

 	default: