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//
// Copyright 2015 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// ProvkingVertexTest:
// Tests on the conformance of the provoking vertex, which applies to flat
// shading and compatibility with D3D. See the section on 'flatshading'
// in the ES 3 specs.
//
#include "test_utils/ANGLETest.h"
using namespace angle;
namespace
{
class ProvokingVertexTest : public ANGLETest
{
protected:
ProvokingVertexTest()
: mProgram(0),
mFramebuffer(0),
mTexture(0),
mTransformFeedback(0),
mBuffer(0),
mIntAttribLocation(-1)
{
setWindowWidth(64);
setWindowHeight(64);
setConfigRedBits(8);
setConfigGreenBits(8);
setConfigBlueBits(8);
setConfigAlphaBits(8);
setConfigDepthBits(24);
}
void SetUp() override
{
ANGLETest::SetUp();
const std::string &vertexShader =
"#version 300 es\n"
"in int intAttrib;\n"
"in vec2 position;\n"
"flat out int attrib;\n"
"void main() {\n"
" gl_Position = vec4(position, 0, 1);\n"
" attrib = intAttrib;\n"
"}";
const std::string &fragmentShader =
"#version 300 es\n"
"flat in int attrib;\n"
"out int fragColor;\n"
"void main() {\n"
" fragColor = attrib;\n"
"}";
std::vector<std::string> tfVaryings;
tfVaryings.push_back("attrib");
mProgram = CompileProgramWithTransformFeedback(vertexShader, fragmentShader, tfVaryings,
GL_SEPARATE_ATTRIBS);
ASSERT_NE(0u, mProgram);
glGenTextures(1, &mTexture);
glBindTexture(GL_TEXTURE_2D, mTexture);
glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32I, getWindowWidth(), getWindowHeight());
glGenFramebuffers(1, &mFramebuffer);
glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTexture, 0);
mIntAttribLocation = glGetAttribLocation(mProgram, "intAttrib");
ASSERT_NE(-1, mIntAttribLocation);
glEnableVertexAttribArray(mIntAttribLocation);
ASSERT_GL_NO_ERROR();
}
void TearDown() override
{
if (mProgram != 0)
{
glDeleteProgram(mProgram);
mProgram = 0;
}
if (mFramebuffer != 0)
{
glDeleteFramebuffers(1, &mFramebuffer);
mFramebuffer = 0;
}
if (mTexture != 0)
{
glDeleteTextures(1, &mTexture);
mTexture = 0;
}
if (mTransformFeedback != 0)
{
glDeleteTransformFeedbacks(1, &mTransformFeedback);
mTransformFeedback = 0;
}
if (mBuffer != 0)
{
glDeleteBuffers(1, &mBuffer);
mBuffer = 0;
}
ANGLETest::TearDown();
}
GLuint mProgram;
GLuint mFramebuffer;
GLuint mTexture;
GLuint mTransformFeedback;
GLuint mBuffer;
GLint mIntAttribLocation;
};
// Test drawing a simple triangle with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest, FlatTriangle)
{
GLint vertexData[] = {1, 2, 3, 1, 2, 3};
glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
drawQuad(mProgram, "position", 0.5f);
GLint pixelValue = 0;
glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
ASSERT_GL_NO_ERROR();
EXPECT_EQ(vertexData[2], pixelValue);
}
// Ensure that any provoking vertex shenanigans still gives correct vertex streams.
TEST_P(ProvokingVertexTest, FlatTriWithTransformFeedback)
{
// TODO(cwallez) figure out why it is broken on AMD on Mac
#if defined(ANGLE_PLATFORM_APPLE)
if (IsAMD())
{
std::cout << "Test skipped on AMD on Mac." << std::endl;
return;
}
#endif
glGenTransformFeedbacks(1, &mTransformFeedback);
glBindTransformFeedback(GL_TRANSFORM_FEEDBACK, mTransformFeedback);
glGenBuffers(1, &mBuffer);
glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, mBuffer);
glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 128, nullptr, GL_STREAM_DRAW);
glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mBuffer);
GLint vertexData[] = {1, 2, 3, 1, 2, 3};
glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
glUseProgram(mProgram);
glBeginTransformFeedback(GL_TRIANGLES);
drawQuad(mProgram, "position", 0.5f);
glEndTransformFeedback();
glUseProgram(0);
GLint pixelValue = 0;
glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
ASSERT_GL_NO_ERROR();
EXPECT_EQ(vertexData[2], pixelValue);
GLvoid *mapPointer =
glMapBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 0, sizeof(int) * 6, GL_MAP_READ_BIT);
ASSERT_NE(nullptr, mapPointer);
int *mappedInts = static_cast<int *>(mapPointer);
for (unsigned int cnt = 0; cnt < 6; ++cnt)
{
EXPECT_EQ(vertexData[cnt], mappedInts[cnt]);
}
}
// Test drawing a simple line with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest, FlatLine)
{
GLfloat halfPixel = 1.0f / static_cast<GLfloat>(getWindowWidth());
GLint vertexData[] = {1, 2};
GLfloat positionData[] = {-1.0f + halfPixel, -1.0f, -1.0f + halfPixel, 1.0f};
glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
GLint positionLocation = glGetAttribLocation(mProgram, "position");
glEnableVertexAttribArray(positionLocation);
glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
glUseProgram(mProgram);
glDrawArrays(GL_LINES, 0, 2);
GLint pixelValue = 0;
glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
ASSERT_GL_NO_ERROR();
EXPECT_EQ(vertexData[1], pixelValue);
}
// Test drawing a simple triangle strip with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest, FlatTriStrip)
{
GLint vertexData[] = {1, 2, 3, 4, 5, 6};
GLfloat positionData[] = {-1.0f, -1.0f, -1.0f, 1.0f, 0.0f, -1.0f,
0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f};
glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
GLint positionLocation = glGetAttribLocation(mProgram, "position");
glEnableVertexAttribArray(positionLocation);
glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
glUseProgram(mProgram);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 6);
std::vector<GLint> pixelBuffer(getWindowWidth() * getWindowHeight(), 0);
glReadPixels(0, 0, getWindowWidth(), getWindowHeight(), GL_RED_INTEGER, GL_INT,
&pixelBuffer[0]);
ASSERT_GL_NO_ERROR();
for (unsigned int triIndex = 0; triIndex < 4; ++triIndex)
{
GLfloat sumX = positionData[triIndex * 2 + 0] + positionData[triIndex * 2 + 2] +
positionData[triIndex * 2 + 4];
GLfloat sumY = positionData[triIndex * 2 + 1] + positionData[triIndex * 2 + 3] +
positionData[triIndex * 2 + 5];
float centerX = sumX / 3.0f * 0.5f + 0.5f;
float centerY = sumY / 3.0f * 0.5f + 0.5f;
unsigned int pixelX =
static_cast<unsigned int>(centerX * static_cast<GLfloat>(getWindowWidth()));
unsigned int pixelY =
static_cast<unsigned int>(centerY * static_cast<GLfloat>(getWindowHeight()));
unsigned int pixelIndex = pixelY * getWindowWidth() + pixelX;
unsigned int provokingVertexIndex = triIndex + 2;
EXPECT_EQ(vertexData[provokingVertexIndex], pixelBuffer[pixelIndex]);
}
}
// Test drawing an indexed triangle strip with flat shading and primitive restart.
TEST_P(ProvokingVertexTest, FlatTriStripPrimitiveRestart)
{
// TODO(jmadill): Implement on the D3D back-end.
if (IsD3D11())
{
std::cout << "Test disabled on D3D11." << std::endl;
return;
}
GLint indexData[] = {0, 1, 2, -1, 1, 2, 3, 4, -1, 3, 4, 5};
GLint vertexData[] = {1, 2, 3, 4, 5, 6};
GLfloat positionData[] = {-1.0f, -1.0f, -1.0f, 1.0f, 0.0f, -1.0f,
0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f};
glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
GLint positionLocation = glGetAttribLocation(mProgram, "position");
glEnableVertexAttribArray(positionLocation);
glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
glDisable(GL_CULL_FACE);
glEnable(GL_PRIMITIVE_RESTART_FIXED_INDEX);
glUseProgram(mProgram);
glDrawElements(GL_TRIANGLE_STRIP, 12, GL_UNSIGNED_INT, indexData);
std::vector<GLint> pixelBuffer(getWindowWidth() * getWindowHeight(), 0);
glReadPixels(0, 0, getWindowWidth(), getWindowHeight(), GL_RED_INTEGER, GL_INT,
&pixelBuffer[0]);
ASSERT_GL_NO_ERROR();
// Account for primitive restart when checking the tris.
GLint triOffsets[] = {0, 4, 5, 9};
for (unsigned int triIndex = 0; triIndex < 4; ++triIndex)
{
GLint vertexA = indexData[triOffsets[triIndex] + 0];
GLint vertexB = indexData[triOffsets[triIndex] + 1];
GLint vertexC = indexData[triOffsets[triIndex] + 2];
GLfloat sumX =
positionData[vertexA * 2] + positionData[vertexB * 2] + positionData[vertexC * 2];
GLfloat sumY = positionData[vertexA * 2 + 1] + positionData[vertexB * 2 + 1] +
positionData[vertexC * 2 + 1];
float centerX = sumX / 3.0f * 0.5f + 0.5f;
float centerY = sumY / 3.0f * 0.5f + 0.5f;
unsigned int pixelX =
static_cast<unsigned int>(centerX * static_cast<GLfloat>(getWindowWidth()));
unsigned int pixelY =
static_cast<unsigned int>(centerY * static_cast<GLfloat>(getWindowHeight()));
unsigned int pixelIndex = pixelY * getWindowWidth() + pixelX;
unsigned int provokingVertexIndex = triIndex + 2;
EXPECT_EQ(vertexData[provokingVertexIndex], pixelBuffer[pixelIndex]);
}
}
ANGLE_INSTANTIATE_TEST(ProvokingVertexTest, ES3_D3D11(), ES3_OPENGL(), ES3_OPENGLES());
} // anonymous namespace
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