draw triangle strip

Makefile

@@ -131,6 +131,7 @@ MAIN_OBJS = \
 	src/main.o \
 	src/glad.o \
 	src/opengl.o \
+	$(patsubst %.glsl,%.glsl.o,$(wildcard src/shader/*.glsl)) \
 	$(GLFW)
 
 main: $(MAIN_OBJS)

include/opengl.h

@@ -4,22 +4,26 @@
 extern "C" {
 #endif
 
-unsigned int compile_shader(const void * vp,
+typedef unsigned int uint;
+
+uint compile_shader(const void * vp,
                     const int vp_length,
                     const void * fp,
                     const int fp_length);
 
-int make_buffer(unsigned int target,
+uint make_buffer(unsigned int target,
                  const void * data,
                  size_t size);
 
-int make_texture(const void * data,
+uint make_texture(const void * data,
                   int internalformat,
                   int width,
                   int height,
                   int format,
                   int type);
 
+uint make_framebuffer(uint * texture, int length);
+
 #ifdef __cplusplus
 }
 #endif

include/shader/test.fs.glsl.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern uint32_t _binary_src_shader_test_fs_glsl_start __asm("_binary_src_shader_test_fs_glsl_start");
+extern uint32_t _binary_src_shader_test_fs_glsl_end __asm("_binary_src_shader_test_fs_glsl_end");
+extern uint32_t _binary_src_shader_test_fs_glsl_size __asm("_binary_src_shader_test_fs_glsl_size");
+
+#define src_shader_test_fs_glsl_start ((const char *)&_binary_src_shader_test_fs_glsl_start)
+#define src_shader_test_fs_glsl_end ((const char *)&_binary_src_shader_test_fs_glsl_end)
+#define src_shader_test_fs_glsl_size (src_shader_test_fs_glsl_end - src_shader_test_fs_glsl_start)
+
+#ifdef __cplusplus
+}
+#endif

include/shader/test.vs.glsl.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern uint32_t _binary_src_shader_test_vs_glsl_start __asm("_binary_src_shader_test_vs_glsl_start");
+extern uint32_t _binary_src_shader_test_vs_glsl_end __asm("_binary_src_shader_test_vs_glsl_end");
+extern uint32_t _binary_src_shader_test_vs_glsl_size __asm("_binary_src_shader_test_vs_glsl_size");
+
+#define src_shader_test_vs_glsl_start ((const char *)&_binary_src_shader_test_vs_glsl_start)
+#define src_shader_test_vs_glsl_end ((const char *)&_binary_src_shader_test_vs_glsl_end)
+#define src_shader_test_vs_glsl_size (src_shader_test_vs_glsl_end - src_shader_test_vs_glsl_start)
+
+#ifdef __cplusplus
+}
+#endif

src/main.c

@@ -8,7 +8,8 @@
 
 #include "opengl.h"
 
-typedef unsigned int uint;
+#include "shader/test.vs.glsl.h"
+#include "shader/test.fs.glsl.h"
 
 int vp_width = 800;
 int vp_height = 600;
@@ -19,6 +20,13 @@ void framebuffer_size_callback(GLFWwindow* window, int width, int height)
   vp_height = height;
 }
 
+const float triangle_array[] = {
+  -1, -1,
+   1, -1,
+  -1,  1,
+   1,  1
+};
+
 int main()
 {
   glfwInitHint(GLFW_PLATFORM, GLFW_PLATFORM_X11);
@@ -51,7 +59,7 @@ int main()
 
   const char * data = "arst";
 
-  make_texture(data,
+  uint texture_input = make_texture(data,
                                     GL_R8, // internalformat
                                     2, // width
                                     2, // height
@@ -65,30 +73,63 @@ int main()
                                           GL_RGBA,
                                           GL_UNSIGNED_BYTE);
 
-  uint fp_framebuffer;
-  glGenFramebuffers(1, &fp_framebuffer);
-  glBindFramebuffer(GL_FRAMEBUFFER, fp_framebuffer);
-  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_framebuffer, 0);
+  uint framebuffer = make_framebuffer(&texture_framebuffer, 1);
 
-  GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
-  assert(status == GL_FRAMEBUFFER_COMPLETE);
+  //////////////////////////////////////////////////////////////////////
+  // shaders
+  //////////////////////////////////////////////////////////////////////
 
-  uint draw_buffers[1] = {GL_COLOR_ATTACHMENT0};
-  glDrawBuffers(1, draw_buffers);
+  uint program_test = compile_shader(src_shader_test_vs_glsl_start,
+                                     src_shader_test_vs_glsl_size,
+                                     src_shader_test_fs_glsl_start,
+                                     src_shader_test_fs_glsl_size);
+
+  //////////////////////////////////////////////////////////////////////
+  // buffers
+  //////////////////////////////////////////////////////////////////////
+
+  uint vertex_buffer = make_buffer(GL_ARRAY_BUFFER,
+                                   triangle_array,
+                                   (sizeof (triangle_array)));
+
+  uint vertex_array;
+  glGenVertexArrays(1, &vertex_array);
+  glBindVertexArray(vertex_array);
+  glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
+  glVertexAttribPointer(0,
+                        2,
+                        GL_FLOAT,
+                        GL_FALSE,
+                        (sizeof (float)) * 2,
+                        (void*)0
+                        );
+  glEnableVertexAttribArray(0);
+  glBindVertexArray(0);
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
 
   while(!glfwWindowShouldClose(window)) {
     if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
       glfwSetWindowShouldClose(window, true);
 
-    glBindFramebuffer(GL_FRAMEBUFFER, fp_framebuffer);
+    /*
+    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+    uint draw_buffers[1] = {GL_COLOR_ATTACHMENT0};
+    glDrawBuffers(1, draw_buffers);
     glViewport(0, 0, 2, 2);
+    */
+    glViewport(0, 0, vp_width, vp_height);
 
-    glClearColor(0.1, 0.2, 0.3, 0.4);
+    glClearColor(0.1, 0.2, 0.0, 0.4);
     glClear(GL_COLOR_BUFFER_BIT);
 
+    glUseProgram(program_test);
+    glBindVertexArray(vertex_array);
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
     //glFlush();
     //glFinish();
 
+    /*
     float out[4 * 2 * 2] = {0};
     glReadPixels(0, 0,
                  2, 2,
@@ -99,8 +140,10 @@ int main()
     for (int i = 0; i < 4 * 2 * 2; i++) {
       printf("%f\n", out[i]);
     }
+    */
+    //printf("swap\n");
 
-    break;
+    glfwSwapBuffers(window);
     glfwPollEvents();
   }
 

src/opengl.c

@@ -1,9 +1,11 @@
 #include <stddef.h>
 #include <stdio.h>
+#include <assert.h>
 
 #include "glad.h"
+#include "opengl.h"
 
-unsigned int compile_shader(const void * vp,
+uint compile_shader(const void * vp,
                     const int vp_length,
                     const void * fp,
                     const int fp_length)
@@ -59,7 +61,7 @@ unsigned int compile_shader(const void * vp,
   return shader_program;
 }
 
-int make_buffer(unsigned int target,
+uint make_buffer(unsigned int target,
                  const void * data,
                  size_t size)
 {
@@ -67,10 +69,12 @@ int make_buffer(unsigned int target,
   glGenBuffers(1, &buffer);
   glBindBuffer(target, buffer);
   glBufferData(target, size, data, GL_STATIC_DRAW);
+
+  glBindBuffer(target, 0);
   return buffer;
 }
 
-int make_texture(const void * data,
+uint make_texture(const void * data,
                   int internalformat,
                   int width,
                   int height,
@@ -88,5 +92,23 @@ int make_texture(const void * data,
 
   glTexImage2D(GL_TEXTURE_2D, 0, internalformat, width, height, 0, format, type, data);
 
+  glBindTexture(GL_TEXTURE_2D, 0);
   return texture;
 }
+
+uint make_framebuffer(uint * texture, int length)
+{
+  uint framebuffer;
+  glGenFramebuffers(1, &framebuffer);
+  glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
+
+  for (int i = 0; i < length; i++) {
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, texture[i], 0);
+  }
+
+  GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+  assert(status == GL_FRAMEBUFFER_COMPLETE);
+
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  return framebuffer;
+}

src/shader/test.fs.glsl

@@ -0,0 +1,10 @@
+#version 330 core
+
+out vec4 fragment_color;
+
+in vec2 f_position;
+
+void main()
+{
+  fragment_color = vec4(f_position, 0, 0);
+}

src/shader/test.vs.glsl

@@ -0,0 +1,12 @@
+#version 330 core
+
+layout (location = 0) in vec2 position;
+
+out vec2 f_position;
+
+void main()
+{
+  f_position = position;
+
+  gl_Position = vec4(position, 0, 1);
+}