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test_triangle.cpp
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test_triangle.cpp
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#include <softrender/glSoft.h>
#include "utils/TestUtil.h"
class TestTriangle:public TestUtil
{
public:
int GetProgram0()
{
const char *vertexShaderSource =
"#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\n";
unsigned int vertexShader;
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
const char *fragmentShaderSource =
"#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n";
unsigned int fragmentShader;
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
unsigned int shaderProgram;
shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
return shaderProgram;
}
int GetProgram1()
{
const char *vertexShaderSource =
"#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\n";
unsigned int vertexShader;
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
const char *fragmentShaderSource =
"#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(1.0f, 1.0f, 0.0f, 1.0f);\n"
"}\n";
unsigned int fragmentShader;
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
unsigned int shaderProgram;
shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
return shaderProgram;
}
unsigned int GetVBO0()
{
float vertices[] = {
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
0.0f, 0.5f, 0.0f
};
unsigned int VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
return VBO;
}
unsigned int GetVBO1()
{
float vertices[] = {
0.5f, 0.5f, 0.0f, // 右上角
0.5f, -0.5f, 0.0f, // 右下角
-0.5f, -0.5f, 0.0f, // 左下角
-0.5f, 0.5f, 0.0f // 左上角
};
unsigned int VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
return VBO;
}
unsigned int GetVBO2()
{
float vertices[] = {
// first triangle
-0.9f, -0.5f, 0.0f, // left
-0.0f, -0.5f, 0.0f, // right
-0.45f, 0.5f, 0.0f, // top
// second triangle
0.0f, -0.5f, 0.0f, // left
0.9f, -0.5f, 0.0f, // right
0.45f, 0.5f, 0.0f // top
};
unsigned int VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
return VBO;
}
void Get2VboVao(unsigned int VBOs[2],unsigned int VAOs[2])
{
float firstTriangle[] = {
-0.9f, -0.5f, 0.0f, // left
-0.0f, -0.5f, 0.0f, // right
-0.45f, 0.5f, 0.0f, // top
};
float secondTriangle[] = {
0.0f, -0.5f, 0.0f, // left
0.9f, -0.5f, 0.0f, // right
0.45f, 0.5f, 0.0f // top
};
glGenVertexArrays(2, VAOs); // we can also generate multiple VAOs or buffers at the same time
glGenBuffers(2, VBOs);
glBindVertexArray(VAOs[0]);
glBindBuffer(GL_ARRAY_BUFFER, VBOs[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(firstTriangle), firstTriangle, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0); // Vertex attributes stay the same
glEnableVertexAttribArray(0);
// glBindVertexArray(0); // no need to unbind at all as we directly bind a different VAO the next few lines
// second triangle setup
// ---------------------
glBindVertexArray(VAOs[1]); // note that we bind to a different VAO now
glBindBuffer(GL_ARRAY_BUFFER, VBOs[1]); // and a different VBO
glBufferData(GL_ARRAY_BUFFER, sizeof(secondTriangle), secondTriangle, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0); // because the vertex data is tightly packed we can also specify 0 as the vertex attribute's stride to let OpenGL figure it out
glEnableVertexAttribArray(0);
}
unsigned int GetIBO0()
{
unsigned int indices[] = { // 注意索引从0开始!
0, 1, 3, // 第一个三角形
1, 2, 3 // 第二个三角形
};
unsigned int EBO;
glGenBuffers(1, &EBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
return EBO;
}
};
TEST_F(TestTriangle, test_vbo)
{
unsigned int VAO;
glGenVertexArrays(1, &VAO);
// 1. 绑定VAO
glBindVertexArray(VAO);
// 2. 把顶点数组复制到缓冲中供OpenGL使用
unsigned int VBO=GetVBO0();
int shaderProgram = GetProgram0();
auto fn=[&](int frame)
{
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
};
PlayWindow(fn,20);
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
}
TEST_F(TestTriangle, test_ibo)
{
unsigned int VAO;
glGenVertexArrays(1, &VAO);
// 1. 绑定顶点数组对象
glBindVertexArray(VAO);
// 2. 把我们的顶点数组复制到一个顶点缓冲中,供OpenGL使用
unsigned VBO=GetVBO1();
// 3. 复制我们的索引数组到一个索引缓冲中,供OpenGL使用
unsigned int EBO=GetIBO0();
int shaderProgram = GetProgram0();
auto fn=[&](int frame)
{
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
};
PlayWindow(fn,20);
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteBuffers(1, &EBO);
glDeleteProgram(shaderProgram);
}
TEST_F(TestTriangle, test_2triangle)
{
unsigned int VAO;
glGenVertexArrays(1, &VAO);
// 1. 绑定VAO
glBindVertexArray(VAO);
// 2. 把顶点数组复制到缓冲中供OpenGL使用
unsigned VBO=GetVBO2();
int shaderProgram = GetProgram0();
auto fn=[&](int frame)
{
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 6);
};
PlayWindow(fn,20);
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
}
TEST_F(TestTriangle, test_2vao)
{
unsigned int VBOs[2], VAOs[2];
Get2VboVao(VBOs,VAOs);
int shaderProgram = GetProgram0();
auto fn=[&](int frame)
{
glUseProgram(shaderProgram);
// draw first triangle using the data from the first VAO
glBindVertexArray(VAOs[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
// then we draw the second triangle using the data from the second VAO
glBindVertexArray(VAOs[1]);
glDrawArrays(GL_TRIANGLES, 0, 3);
};
PlayWindow(fn,20);
glDeleteVertexArrays(2, VAOs);
glDeleteBuffers(2, VBOs);
glDeleteProgram(shaderProgram);
}
TEST_F(TestTriangle, test_2prog)
{
unsigned int VBOs[2], VAOs[2];
Get2VboVao(VBOs,VAOs);
int shaderProgramOrange = GetProgram0();
int shaderProgramYellow = GetProgram1();
auto fn=[&](int frame)
{
// now when we draw the triangle we first use the vertex and orange fragment shader from the first program
glUseProgram(shaderProgramOrange);
// draw the first triangle using the data from our first VAO
glBindVertexArray(VAOs[0]);
glDrawArrays(GL_TRIANGLES, 0, 3); // this call should output an orange triangle
// then we draw the second triangle using the data from the second VAO
// when we draw the second triangle we want to use a different shader program so we switch to the shader program with our yellow fragment shader.
glUseProgram(shaderProgramYellow);
glBindVertexArray(VAOs[1]);
glDrawArrays(GL_TRIANGLES, 0, 3); // this call should output a yellow triangle
};
PlayWindow(fn,20);
glDeleteVertexArrays(2, VAOs);
glDeleteBuffers(2, VBOs);
glDeleteProgram(shaderProgramOrange);
glDeleteProgram(shaderProgramYellow);
}