1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include <GLES2/gl2.h>
6#include <GLES2/gl2ext.h>
7
8#include "gpu/command_buffer/tests/gl_manager.h"
9#include "gpu/command_buffer/tests/gl_test_utils.h"
10#include "testing/gmock/include/gmock/gmock.h"
11#include "testing/gtest/include/gtest/gtest.h"
12
13#define SHADER(Src) #Src
14
15namespace gpu {
16
17class PointCoordTest : public testing::Test {
18 public:
19  static const GLsizei kResolution = 256;
20
21 protected:
22  virtual void SetUp() {
23    GLManager::Options options;
24    options.size = gfx::Size(kResolution, kResolution);
25    gl_.Initialize(options);
26  }
27
28  virtual void TearDown() {
29    gl_.Destroy();
30  }
31
32  GLuint SetupQuad(GLint position_location, GLfloat pixel_offset);
33
34  GLManager gl_;
35};
36
37GLuint PointCoordTest::SetupQuad(
38    GLint position_location, GLfloat pixel_offset) {
39  GLuint vbo = 0;
40  glGenBuffers(1, &vbo);
41  glBindBuffer(GL_ARRAY_BUFFER, vbo);
42  float vertices[] = {
43    -0.5f + pixel_offset, -0.5f + pixel_offset,
44     0.5f + pixel_offset, -0.5f + pixel_offset,
45    -0.5f + pixel_offset,  0.5f + pixel_offset,
46     0.5f + pixel_offset,  0.5f + pixel_offset,
47  };
48  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
49  glEnableVertexAttribArray(position_location);
50  glVertexAttribPointer(position_location, 2, GL_FLOAT, GL_FALSE, 0, 0);
51
52  return vbo;
53}
54
55namespace {
56
57struct FormatType {
58  GLenum format;
59  GLenum type;
60};
61
62GLfloat s2p(GLfloat s) {
63  return (s + 1.0) * 0.5 * PointCoordTest::kResolution;
64}
65
66}  // anonymous namespace
67
68// crbug.com/162976
69// Flaky on Linux ATI bot.
70#if (defined(OS_LINUX) && defined(NDEBUG))
71#define MAYBE_RenderTo DISABLED_RenderTo
72#else
73#define MAYBE_RenderTo RenderTo
74#endif
75
76TEST_F(PointCoordTest, MAYBE_RenderTo) {
77  static const char* v_shader_str = SHADER(
78      attribute vec4 a_position;
79      uniform float u_pointsize;
80      void main()
81      {
82        gl_PointSize = u_pointsize;
83        gl_Position = a_position;
84      }
85  );
86  static const char* f_shader_str = SHADER(
87      precision mediump float;
88      void main()
89      {
90        gl_FragColor = vec4(
91          gl_PointCoord.x,
92          gl_PointCoord.y,
93          0,
94          1);
95      }
96  );
97
98  GLuint program = GLTestHelper::LoadProgram(v_shader_str, f_shader_str);
99  glUseProgram(program);
100
101  GLint position_loc = glGetAttribLocation(program, "a_position");
102  GLint pointsize_loc = glGetUniformLocation(program, "u_pointsize");
103
104  GLint range[2] = { 0, 0 };
105  glGetIntegerv(GL_ALIASED_POINT_SIZE_RANGE, &range[0]);
106  GLint max_point_size = range[1];
107  EXPECT_GE(max_point_size, 1);
108
109  max_point_size = std::min(max_point_size, 64);
110  GLint point_width = max_point_size / kResolution;
111  GLint point_step = max_point_size / 4;
112  point_step = std::max(1, point_step);
113
114  glUniform1f(pointsize_loc, max_point_size);
115
116  GLfloat pixel_offset = (max_point_size % 2) ? (1.0f / kResolution) : 0;
117
118  SetupQuad(position_loc, pixel_offset);
119
120  glClear(GL_COLOR_BUFFER_BIT);
121  glDrawArrays(GL_POINTS, 0, 4);
122
123  for (GLint py = 0; py < 2; ++py) {
124    for (GLint px = 0; px < 2; ++px) {
125      GLfloat point_x = -0.5 + px + pixel_offset;
126      GLfloat point_y = -0.5 + py + pixel_offset;
127      for (GLint yy = 0; yy < max_point_size; yy += point_step) {
128        for (GLint xx = 0; xx < max_point_size; xx += point_step) {
129          // formula for s and t from OpenGL ES 2.0 spec section 3.3
130          GLfloat xw = s2p(point_x);
131          GLfloat yw = s2p(point_y);
132          GLfloat u = xx / max_point_size * 2 - 1;
133          GLfloat v = yy / max_point_size * 2 - 1;
134          GLint xf = s2p(point_x + u * point_width);
135          GLint yf = s2p(point_y + v * point_width);
136          GLfloat s = 0.5 + (xf + 0.5 - xw) / max_point_size;
137          GLfloat t = 0.5 + (yf + 0.5 - yw) / max_point_size;
138          uint8 color[4] = {
139            static_cast<uint8>(s * 255),
140            static_cast<uint8>((1 - t) * 255),
141            0,
142            255,
143          };
144          GLTestHelper::CheckPixels(xf, yf, 1, 1, 4, color);
145        }
146      }
147    }
148  }
149
150  GLTestHelper::CheckGLError("no errors", __LINE__);
151}
152
153}  // namespace gpu
154
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157