1 //
2 // Copyright 2015 The ANGLE Project Authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
5 //
6 // ProvkingVertexTest:
7 // Tests on the conformance of the provoking vertex, which applies to flat
8 // shading and compatibility with D3D. See the section on 'flatshading'
9 // in the ES 3 specs.
10 //
11
12 #include "test_utils/ANGLETest.h"
13
14 using namespace angle;
15
16 namespace
17 {
18
19 class ProvokingVertexTest : public ANGLETest
20 {
21 protected:
ProvokingVertexTest()22 ProvokingVertexTest()
23 : mProgram(0),
24 mFramebuffer(0),
25 mTexture(0),
26 mTransformFeedback(0),
27 mBuffer(0),
28 mIntAttribLocation(-1)
29 {
30 setWindowWidth(64);
31 setWindowHeight(64);
32 setConfigRedBits(8);
33 setConfigGreenBits(8);
34 setConfigBlueBits(8);
35 setConfigAlphaBits(8);
36 setConfigDepthBits(24);
37 }
38
SetUp()39 void SetUp() override
40 {
41 ANGLETest::SetUp();
42
43 const std::string &vertexShader =
44 "#version 300 es\n"
45 "in int intAttrib;\n"
46 "in vec2 position;\n"
47 "flat out int attrib;\n"
48 "void main() {\n"
49 " gl_Position = vec4(position, 0, 1);\n"
50 " attrib = intAttrib;\n"
51 "}";
52
53 const std::string &fragmentShader =
54 "#version 300 es\n"
55 "flat in int attrib;\n"
56 "out int fragColor;\n"
57 "void main() {\n"
58 " fragColor = attrib;\n"
59 "}";
60
61 std::vector<std::string> tfVaryings;
62 tfVaryings.push_back("attrib");
63 mProgram = CompileProgramWithTransformFeedback(vertexShader, fragmentShader, tfVaryings,
64 GL_SEPARATE_ATTRIBS);
65 ASSERT_NE(0u, mProgram);
66
67 glGenTextures(1, &mTexture);
68 glBindTexture(GL_TEXTURE_2D, mTexture);
69 glTexStorage2D(GL_TEXTURE_2D, 1, GL_R32I, getWindowWidth(), getWindowHeight());
70
71 glGenFramebuffers(1, &mFramebuffer);
72 glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
73 glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTexture, 0);
74
75 mIntAttribLocation = glGetAttribLocation(mProgram, "intAttrib");
76 ASSERT_NE(-1, mIntAttribLocation);
77 glEnableVertexAttribArray(mIntAttribLocation);
78
79 ASSERT_GL_NO_ERROR();
80 }
81
TearDown()82 void TearDown() override
83 {
84 if (mProgram != 0)
85 {
86 glDeleteProgram(mProgram);
87 mProgram = 0;
88 }
89
90 if (mFramebuffer != 0)
91 {
92 glDeleteFramebuffers(1, &mFramebuffer);
93 mFramebuffer = 0;
94 }
95
96 if (mTexture != 0)
97 {
98 glDeleteTextures(1, &mTexture);
99 mTexture = 0;
100 }
101
102 if (mTransformFeedback != 0)
103 {
104 glDeleteTransformFeedbacks(1, &mTransformFeedback);
105 mTransformFeedback = 0;
106 }
107
108 if (mBuffer != 0)
109 {
110 glDeleteBuffers(1, &mBuffer);
111 mBuffer = 0;
112 }
113
114 ANGLETest::TearDown();
115 }
116
117 GLuint mProgram;
118 GLuint mFramebuffer;
119 GLuint mTexture;
120 GLuint mTransformFeedback;
121 GLuint mBuffer;
122 GLint mIntAttribLocation;
123 };
124
125 // Test drawing a simple triangle with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest,FlatTriangle)126 TEST_P(ProvokingVertexTest, FlatTriangle)
127 {
128 GLint vertexData[] = {1, 2, 3, 1, 2, 3};
129 glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
130
131 drawQuad(mProgram, "position", 0.5f);
132
133 GLint pixelValue = 0;
134 glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
135
136 ASSERT_GL_NO_ERROR();
137 EXPECT_EQ(vertexData[2], pixelValue);
138 }
139
140 // Ensure that any provoking vertex shenanigans still gives correct vertex streams.
TEST_P(ProvokingVertexTest,FlatTriWithTransformFeedback)141 TEST_P(ProvokingVertexTest, FlatTriWithTransformFeedback)
142 {
143 // TODO(cwallez) figure out why it is broken on AMD on Mac
144 #if defined(ANGLE_PLATFORM_APPLE)
145 if (IsAMD())
146 {
147 std::cout << "Test skipped on AMD on Mac." << std::endl;
148 return;
149 }
150 #endif
151
152 glGenTransformFeedbacks(1, &mTransformFeedback);
153 glBindTransformFeedback(GL_TRANSFORM_FEEDBACK, mTransformFeedback);
154
155 glGenBuffers(1, &mBuffer);
156 glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, mBuffer);
157 glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 128, nullptr, GL_STREAM_DRAW);
158
159 glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mBuffer);
160
161 GLint vertexData[] = {1, 2, 3, 1, 2, 3};
162 glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
163
164 glUseProgram(mProgram);
165 glBeginTransformFeedback(GL_TRIANGLES);
166 drawQuad(mProgram, "position", 0.5f);
167 glEndTransformFeedback();
168 glUseProgram(0);
169
170 GLint pixelValue = 0;
171 glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
172
173 ASSERT_GL_NO_ERROR();
174 EXPECT_EQ(vertexData[2], pixelValue);
175
176 GLvoid *mapPointer =
177 glMapBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 0, sizeof(int) * 6, GL_MAP_READ_BIT);
178 ASSERT_NE(nullptr, mapPointer);
179
180 int *mappedInts = static_cast<int *>(mapPointer);
181 for (unsigned int cnt = 0; cnt < 6; ++cnt)
182 {
183 EXPECT_EQ(vertexData[cnt], mappedInts[cnt]);
184 }
185 }
186
187 // Test drawing a simple line with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest,FlatLine)188 TEST_P(ProvokingVertexTest, FlatLine)
189 {
190 GLfloat halfPixel = 1.0f / static_cast<GLfloat>(getWindowWidth());
191
192 GLint vertexData[] = {1, 2};
193 GLfloat positionData[] = {-1.0f + halfPixel, -1.0f, -1.0f + halfPixel, 1.0f};
194
195 glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
196
197 GLint positionLocation = glGetAttribLocation(mProgram, "position");
198 glEnableVertexAttribArray(positionLocation);
199 glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
200
201 glUseProgram(mProgram);
202 glDrawArrays(GL_LINES, 0, 2);
203
204 GLint pixelValue = 0;
205 glReadPixels(0, 0, 1, 1, GL_RED_INTEGER, GL_INT, &pixelValue);
206
207 ASSERT_GL_NO_ERROR();
208 EXPECT_EQ(vertexData[1], pixelValue);
209 }
210
211 // Test drawing a simple triangle strip with flat shading, and different valued vertices.
TEST_P(ProvokingVertexTest,FlatTriStrip)212 TEST_P(ProvokingVertexTest, FlatTriStrip)
213 {
214 GLint vertexData[] = {1, 2, 3, 4, 5, 6};
215 GLfloat positionData[] = {-1.0f, -1.0f, -1.0f, 1.0f, 0.0f, -1.0f,
216 0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f};
217
218 glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
219
220 GLint positionLocation = glGetAttribLocation(mProgram, "position");
221 glEnableVertexAttribArray(positionLocation);
222 glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
223
224 glUseProgram(mProgram);
225 glDrawArrays(GL_TRIANGLE_STRIP, 0, 6);
226
227 std::vector<GLint> pixelBuffer(getWindowWidth() * getWindowHeight(), 0);
228 glReadPixels(0, 0, getWindowWidth(), getWindowHeight(), GL_RED_INTEGER, GL_INT,
229 &pixelBuffer[0]);
230
231 ASSERT_GL_NO_ERROR();
232
233 for (unsigned int triIndex = 0; triIndex < 4; ++triIndex)
234 {
235 GLfloat sumX = positionData[triIndex * 2 + 0] + positionData[triIndex * 2 + 2] +
236 positionData[triIndex * 2 + 4];
237 GLfloat sumY = positionData[triIndex * 2 + 1] + positionData[triIndex * 2 + 3] +
238 positionData[triIndex * 2 + 5];
239
240 float centerX = sumX / 3.0f * 0.5f + 0.5f;
241 float centerY = sumY / 3.0f * 0.5f + 0.5f;
242 unsigned int pixelX =
243 static_cast<unsigned int>(centerX * static_cast<GLfloat>(getWindowWidth()));
244 unsigned int pixelY =
245 static_cast<unsigned int>(centerY * static_cast<GLfloat>(getWindowHeight()));
246 unsigned int pixelIndex = pixelY * getWindowWidth() + pixelX;
247
248 unsigned int provokingVertexIndex = triIndex + 2;
249
250 EXPECT_EQ(vertexData[provokingVertexIndex], pixelBuffer[pixelIndex]);
251 }
252 }
253
254 // Test drawing an indexed triangle strip with flat shading and primitive restart.
TEST_P(ProvokingVertexTest,FlatTriStripPrimitiveRestart)255 TEST_P(ProvokingVertexTest, FlatTriStripPrimitiveRestart)
256 {
257 // TODO(jmadill): Implement on the D3D back-end.
258 if (IsD3D11())
259 {
260 std::cout << "Test disabled on D3D11." << std::endl;
261 return;
262 }
263
264 GLint indexData[] = {0, 1, 2, -1, 1, 2, 3, 4, -1, 3, 4, 5};
265 GLint vertexData[] = {1, 2, 3, 4, 5, 6};
266 GLfloat positionData[] = {-1.0f, -1.0f, -1.0f, 1.0f, 0.0f, -1.0f,
267 0.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f};
268
269 glVertexAttribIPointer(mIntAttribLocation, 1, GL_INT, 0, vertexData);
270
271 GLint positionLocation = glGetAttribLocation(mProgram, "position");
272 glEnableVertexAttribArray(positionLocation);
273 glVertexAttribPointer(positionLocation, 2, GL_FLOAT, GL_FALSE, 0, positionData);
274
275 glDisable(GL_CULL_FACE);
276 glEnable(GL_PRIMITIVE_RESTART_FIXED_INDEX);
277 glUseProgram(mProgram);
278 glDrawElements(GL_TRIANGLE_STRIP, 12, GL_UNSIGNED_INT, indexData);
279
280 std::vector<GLint> pixelBuffer(getWindowWidth() * getWindowHeight(), 0);
281 glReadPixels(0, 0, getWindowWidth(), getWindowHeight(), GL_RED_INTEGER, GL_INT,
282 &pixelBuffer[0]);
283
284 ASSERT_GL_NO_ERROR();
285
286 // Account for primitive restart when checking the tris.
287 GLint triOffsets[] = {0, 4, 5, 9};
288
289 for (unsigned int triIndex = 0; triIndex < 4; ++triIndex)
290 {
291 GLint vertexA = indexData[triOffsets[triIndex] + 0];
292 GLint vertexB = indexData[triOffsets[triIndex] + 1];
293 GLint vertexC = indexData[triOffsets[triIndex] + 2];
294
295 GLfloat sumX =
296 positionData[vertexA * 2] + positionData[vertexB * 2] + positionData[vertexC * 2];
297 GLfloat sumY = positionData[vertexA * 2 + 1] + positionData[vertexB * 2 + 1] +
298 positionData[vertexC * 2 + 1];
299
300 float centerX = sumX / 3.0f * 0.5f + 0.5f;
301 float centerY = sumY / 3.0f * 0.5f + 0.5f;
302 unsigned int pixelX =
303 static_cast<unsigned int>(centerX * static_cast<GLfloat>(getWindowWidth()));
304 unsigned int pixelY =
305 static_cast<unsigned int>(centerY * static_cast<GLfloat>(getWindowHeight()));
306 unsigned int pixelIndex = pixelY * getWindowWidth() + pixelX;
307
308 unsigned int provokingVertexIndex = triIndex + 2;
309
310 EXPECT_EQ(vertexData[provokingVertexIndex], pixelBuffer[pixelIndex]);
311 }
312 }
313
314 ANGLE_INSTANTIATE_TEST(ProvokingVertexTest, ES3_D3D11(), ES3_OPENGL(), ES3_OPENGLES());
315
316 } // anonymous namespace
317