Added PointSprites Support for renderers that do not support Geometry Shaders
Change-Id: Iae9ac5f8fbba68dba5e49ccda7bb7eebb05c8e9a
Reviewed-on: https://chromium-review.googlesource.com/240450
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/d3d/DynamicHLSL.cpp b/src/libANGLE/renderer/d3d/DynamicHLSL.cpp
index e7deac9..5a2a781 100644
--- a/src/libANGLE/renderer/d3d/DynamicHLSL.cpp
+++ b/src/libANGLE/renderer/d3d/DynamicHLSL.cpp
@@ -420,6 +420,22 @@
}
}
+ // If gl_PointSize is used in the shader then pointsprites rendering is expected.
+ // If the renderer does not support Geometry shaders then Instanced PointSprite emulation
+ // may must be used.
+ bool usesPointSize = sourceShader.find("GL_USES_POINT_SIZE") != std::string::npos;
+ bool useInstancedPointSpriteEmulation = usesPointSize && mRenderer->getWorkarounds().useInstancedPointSpriteEmulation;
+
+ // Instanced PointSprite emulation requires additional entries in the
+ // VS_INPUT structure to support the vertices that make up the quad vertices.
+ // These values must be in sync with the cooresponding values added during inputlayout creation
+ // in InputLayoutCache::applyVertexBuffers().
+ if (useInstancedPointSpriteEmulation)
+ {
+ structHLSL += " float3 spriteVertexPos : SPRITEPOSITION0;\n";
+ structHLSL += " float2 spriteTexCoord : SPRITETEXCOORD0;\n";
+ }
+
std::string replacementHLSL = "struct VS_INPUT\n"
"{\n" +
structHLSL +
@@ -694,6 +710,7 @@
bool usesFragCoord = fragmentShader->mUsesFragCoord;
bool usesPointCoord = fragmentShader->mUsesPointCoord;
bool usesPointSize = vertexShader->mUsesPointSize;
+ bool useInstancedPointSpriteEmulation = usesPointSize && mRenderer->getWorkarounds().useInstancedPointSpriteEmulation;
if (usesFragColor && usesFragData)
{
@@ -720,12 +737,27 @@
}
const std::string &varyingHLSL = generateVaryingHLSL(vertexShader);
+
+ // Instanced PointSprite emulation requires that gl_PointCoord is present in the vertex shader VS_OUTPUT
+ // structure to ensure compatibility with the generated PS_INPUT of the pixel shader.
+ // GeometryShader PointSprite emulation does not require this additional entry because the
+ // GS_OUTPUT of the Geometry shader contains the pointCoord value and already matches the PS_INPUT of the
+ // generated pixel shader.
const SemanticInfo &vertexSemantics = getSemanticInfo(registers, usesFragCoord,
- false, usesPointSize, false);
+ (useInstancedPointSpriteEmulation && usesPointCoord),
+ usesPointSize, false);
storeUserLinkedVaryings(vertexShader, linkedVaryings);
storeBuiltinLinkedVaryings(vertexSemantics, linkedVaryings);
+ // Instanced PointSprite emulation requires additional entries originally generated in the
+ // GeometryShader HLSL. These include pointsize clamp values.
+ if (useInstancedPointSpriteEmulation)
+ {
+ vertexHLSL += "static float minPointSize = " + Str((int)mRenderer->getRendererCaps().minAliasedPointSize) + ".0f;\n"
+ "static float maxPointSize = " + Str((int)mRenderer->getRendererCaps().maxAliasedPointSize) + ".0f;\n";
+ }
+
// Add stub string to be replaced when shader is dynamically defined by its layout
vertexHLSL += "\n" + VERTEX_ATTRIBUTE_STUB_STRING + "\n"
"struct VS_OUTPUT\n" + generateVaryingLinkHLSL(vertexSemantics, varyingHLSL) + "\n"
@@ -802,6 +834,22 @@
}
}
+ // Instanced PointSprite emulation requires additional entries to calculate
+ // the final output vertex positions of the quad that represents each sprite.
+ if (useInstancedPointSpriteEmulation)
+ {
+ vertexHLSL += "\n"
+ " gl_PointSize = clamp(gl_PointSize, minPointSize, maxPointSize);\n"
+ " output.dx_Position.xyz += float3(input.spriteVertexPos.x * gl_PointSize / (dx_ViewCoords.x*2), input.spriteVertexPos.y * gl_PointSize / (dx_ViewCoords.y*2), input.spriteVertexPos.z) * output.dx_Position.w;\n"
+ " output.gl_PointSize = gl_PointSize;\n";
+
+ if (usesPointCoord)
+ {
+ vertexHLSL += "\n"
+ " output.gl_PointCoord = input.spriteTexCoord;\n";
+ }
+ }
+
vertexHLSL += "\n"
" return output;\n"
"}\n";