cave-story-solaris/src/Backends/GLFW3/Window-Software.cpp
Clownacy 3ffe5a083e Use fixed-size texture format
I recall reading that you should prefer these over the non-fixed size
2020-04-15 16:59:54 +01:00

151 lines
3.9 KiB
C++

#include "../Window-Software.h"
#include "Window.h"
#include <stddef.h>
#include <stdlib.h>
#if defined(__APPLE__)
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif
#include <GLFW/glfw3.h>
#include "../Misc.h"
GLFWwindow *window;
static unsigned char *framebuffer;
static int framebuffer_width;
static int framebuffer_height;
static float framebuffer_x_ratio;
static float framebuffer_y_ratio;
static GLuint screen_texture_id;
unsigned char* WindowBackend_Software_CreateWindow(const char *window_title, int screen_width, int screen_height, bool fullscreen, size_t *pitch)
{
glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_API);
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 1);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
framebuffer_width = screen_width;
framebuffer_height = screen_height;
GLFWmonitor *monitor = NULL;
if (fullscreen)
{
monitor = glfwGetPrimaryMonitor();
if (monitor != NULL)
{
const GLFWvidmode *mode = glfwGetVideoMode(monitor);
screen_width = mode->width;
screen_height = mode->height;
}
}
window = glfwCreateWindow(screen_width, screen_height, window_title, monitor, NULL);
if (window != NULL)
{
glfwMakeContextCurrent(window);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glEnable(GL_TEXTURE_2D);
WindowBackend_Software_HandleWindowResize(screen_width, screen_height);
// Create screen texture
glGenTextures(1, &screen_texture_id);
glBindTexture(GL_TEXTURE_2D, screen_texture_id);
int framebuffer_texture_width = 1;
while (framebuffer_texture_width < framebuffer_width)
framebuffer_texture_width <<= 1;
int framebuffer_texture_height = 1;
while (framebuffer_texture_height < framebuffer_height)
framebuffer_texture_height <<= 1;
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, framebuffer_texture_width, framebuffer_texture_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
framebuffer_x_ratio = (float)framebuffer_width / framebuffer_texture_width;
framebuffer_y_ratio = (float)framebuffer_height / framebuffer_texture_height;
framebuffer = (unsigned char*)malloc(framebuffer_width * framebuffer_height * 3);
*pitch = framebuffer_width * 3;
Backend_PostWindowCreation();
return framebuffer;
}
else
{
Backend_ShowMessageBox("Fatal error (OpenGL rendering backend)", "Could not create window");
}
return NULL;
}
void WindowBackend_Software_DestroyWindow(void)
{
free(framebuffer);
glDeleteTextures(1, &screen_texture_id);
glfwDestroyWindow(window);
}
void WindowBackend_Software_Display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, framebuffer_width, framebuffer_height, GL_RGB, GL_UNSIGNED_BYTE, framebuffer);
glBegin(GL_TRIANGLE_STRIP);
glTexCoord2f(0.0f, framebuffer_y_ratio);
glVertex2f(-1.0f, -1.0f);
glTexCoord2f(framebuffer_x_ratio, framebuffer_y_ratio);
glVertex2f(1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f);
glVertex2f(-1.0f, 1.0f);
glTexCoord2f(framebuffer_x_ratio, 0.0f);
glVertex2f(1.0f, 1.0f);
glEnd();
glfwSwapBuffers(window);
}
void WindowBackend_Software_HandleWindowResize(unsigned int width, unsigned int height)
{
// Do some viewport trickery, to fit the framebuffer in the center of the screen
GLint viewport_x;
GLint viewport_y;
GLsizei viewport_width;
GLsizei viewport_height;
if ((float)width / (float)height > (float)framebuffer_width / (float)framebuffer_height)
{
viewport_y = 0;
viewport_height = height;
viewport_width = framebuffer_width * ((float)height / (float)framebuffer_height);
viewport_x = (width - viewport_width) / 2;
}
else
{
viewport_x = 0;
viewport_width = width;
viewport_height = framebuffer_height * ((float)width / (float)framebuffer_width);
viewport_y = (height - viewport_height) / 2;
}
glViewport(viewport_x, viewport_y, viewport_width, viewport_height);
}