Convert cursor test to GL2

This commit is contained in:
Camilla Berglund 2016-09-19 14:49:15 +02:00
parent 0090ce3df7
commit f7584bf14c

View File

@ -42,8 +42,24 @@
#include <stdio.h>
#include <stdlib.h>
#include "linmath.h"
#define CURSOR_FRAME_COUNT 60
static const char* vertex_shader_text =
"uniform mat4 MVP;\n"
"attribute vec2 vPos;\n"
"void main()\n"
"{\n"
" gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n"
"}\n";
static const char* fragment_shader_text =
"void main()\n"
"{\n"
" gl_FragColor = vec4(1.0);\n"
"}\n";
static double cursor_x;
static double cursor_y;
static int swap_interval = 1;
@ -196,6 +212,8 @@ int main(void)
GLFWwindow* window;
GLFWcursor* star_cursors[CURSOR_FRAME_COUNT];
GLFWcursor* current_frame = NULL;
GLuint vertex_buffer, vertex_shader, fragment_shader, program;
GLint mvp_location, vpos_location;
glfwSetErrorCallback(error_callback);
@ -231,6 +249,9 @@ int main(void)
}
}
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
window = glfwCreateWindow(640, 480, "Cursor Test", NULL, NULL);
if (!window)
{
@ -241,6 +262,30 @@ int main(void)
glfwMakeContextCurrent(window);
gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
glGenBuffers(1, &vertex_buffer);
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
vertex_shader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL);
glCompileShader(vertex_shader);
fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL);
glCompileShader(fragment_shader);
program = glCreateProgram();
glAttachShader(program, vertex_shader);
glAttachShader(program, fragment_shader);
glLinkProgram(program);
mvp_location = glGetUniformLocation(program, "MVP");
vpos_location = glGetAttribLocation(program, "vPos");
glEnableVertexAttribArray(vpos_location);
glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE,
sizeof(vec2), (void*) 0);
glUseProgram(program);
glfwGetCursorPos(window, &cursor_x, &cursor_y);
printf("Cursor position: %f %f\n", cursor_x, cursor_y);
@ -255,24 +300,33 @@ int main(void)
{
int wnd_width, wnd_height, fb_width, fb_height;
float scale;
vec2 vertices[4];
mat4x4 mvp;
glfwGetWindowSize(window, &wnd_width, &wnd_height);
glfwGetFramebufferSize(window, &fb_width, &fb_height);
scale = (float) fb_width / (float) wnd_width;
glViewport(0, 0, fb_width, fb_height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.f, fb_width, 0.f, fb_height, 0.f, 1.f);
scale = (float) fb_width / (float) wnd_width;
vertices[0][0] = 0.f;
vertices[0][1] = fb_height - cursor_y * scale;
vertices[1][0] = (float) fb_width;
vertices[1][1] = fb_height - cursor_y * scale;
vertices[2][0] = cursor_x * scale;
vertices[2][1] = 0.f;
vertices[3][0] = cursor_x * scale;
vertices[3][1] = (float) fb_height;
glBegin(GL_LINES);
glVertex2f(0.f, (GLfloat) (fb_height - cursor_y * scale));
glVertex2f((GLfloat) fb_width, (GLfloat) (fb_height - cursor_y * scale));
glVertex2f((GLfloat) cursor_x * scale, 0.f);
glVertex2f((GLfloat) cursor_x * scale, (GLfloat) fb_height);
glEnd();
glBufferData(GL_ARRAY_BUFFER,
sizeof(vertices),
vertices,
GL_STREAM_DRAW);
mat4x4_ortho(mvp, 0.f, fb_width, 0.f, fb_height, 0.f, 1.f);
glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp);
glDrawArrays(GL_LINES, 0, 4);
}
glfwSwapBuffers(window);