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/*********************************************************************************************
*
* raylib.textures
*
* Basic functions to load and draw Textures (2d)
*
* Uses external lib:
* stb_image - Multiple formats image loading (JPEG, PNG, BMP, TGA, PSD, GIF, PIC)
*
* Copyright (c) 2013 Ramon Santamaria (Ray San - raysan@raysanweb.com)
*
* This software is provided "as-is", without any express or implied warranty. In no event
* will the authors be held liable for any damages arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose, including commercial
* applications, and to alter it and redistribute it freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not claim that you
* wrote the original software. If you use this software in a product, an acknowledgment
* in the product documentation would be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be misrepresented
* as being the original software.
*
* 3. This notice may not be removed or altered from any source distribution.
*
**********************************************************************************************/
#include "raylib.h"
#include <GL/gl.h> // OpenGL functions
#include <stdlib.h> // Declares malloc() and free() for memory management
#include "stb_image.h" // Used to read image data (multiple formats support)
//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
// Nop...
//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
typedef unsigned char byte;
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
// It's lonely here...
//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
// No private (static) functions in this module (.c file)
//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
// Load an image into CPU memory (RAM)
Image LoadImage(const char *fileName)
{
Image image;
int imgWidth;
int imgHeight;
int imgBpp;
// NOTE: Using stb_image to load images (Supports: BMP, TGA, PNG, JPG, ...)
byte *imgData = stbi_load(fileName, &imgWidth, &imgHeight, &imgBpp, 4); // Force loading to 4 components (RGBA)
// Convert array to pixel array for working convenience
image.pixels = (Color *)malloc(imgWidth * imgHeight * sizeof(Color));
int pix = 0;
for (int i = 0; i < (imgWidth * imgHeight * 4); i += 4)
{
image.pixels[pix].r = imgData[i];
image.pixels[pix].g = imgData[i+1];
image.pixels[pix].b = imgData[i+2];
image.pixels[pix].a = imgData[i+3];
pix++;
}
stbi_image_free(imgData);
image.width = imgWidth;
image.height = imgHeight;
// ALTERNATIVE: We can load pixel data directly into Color struct pixels array,
// to do that struct data alignment should be the right one (4 byte); it is.
//image.pixels = stbi_load(fileName, &imgWidth, &imgHeight, &imgBpp, 4);
return image;
}
// Unload image from CPU memory (RAM)
void UnloadImage(Image image)
{
free(image.pixels);
}
// Load an image as texture into GPU memory
Texture2D LoadTexture(const char *fileName)
{
Texture2D texture;
int imgWidth;
int imgHeight;
int imgBpp;
// NOTE: Using stb_image to load images (Supports: BMP, TGA, PNG, JPG, ...)
byte *imgData = stbi_load(fileName, &imgWidth, &imgHeight, &imgBpp, 4); // Force loading to 4 components (RGBA)
// Convert loaded data to OpenGL texture
//----------------------------------------
GLuint id;
glGenTextures(1, &id); // Generate Pointer to the Texture
glBindTexture(GL_TEXTURE_2D, id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); // Set texture to repead on x-axis
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); // Set texture to repead on y-axis
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // Filter for pixel-perfect drawing, alternative: GL_LINEAR
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); // Filter for pixel-perfect drawing, alternative: GL_LINEAR
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, imgWidth, imgHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, imgData);
// NOTE: Not using mipmappings (texture for 2D drawing)
// At this point we have the image converted to texture and uploaded to GPU
stbi_image_free(imgData); // Now we can free loaded data from RAM memory
texture.glId = id;
texture.width = imgWidth;
texture.height = imgHeight;
return texture;
}
// Load an image as texture (and convert to POT with mipmaps)
Texture2D LoadTextureEx(const char *fileName, bool createPOT, bool mipmaps)
{
Texture2D texture;
// TODO: Load and image and convert to Power-Of-Two
// NOTE: Conversion could be done just adding extra space to image or by scaling image
// NOTE: If scaling image, be careful with scaling algorithm (aproximation, bilinear, bicubic...)
// TODO: Generate all required mipmap levels from image and convert to testure (not that easy)
// NOTE: If using OpenGL 1.1, the only option is doing mipmap generation on CPU side (i.e. gluBuild2DMipmaps)
// NOTE: raylib tries to minimize external dependencies so, we are not using GLU
// NOTE: Re-implement some function similar to gluBuild2DMipmaps (not that easy...)
return texture;
}
// Unload texture from GPU memory
void UnloadTexture(Texture2D texture)
{
glDeleteTextures(1, &texture.glId);
}
// Draw a Texture2D
void DrawTexture(Texture2D texture, int posX, int posY, Color tint)
{
DrawTextureEx(texture, (Vector2){ (float)posX, (float)posY}, 0, 1.0f, tint);
}
// Draw a Texture2D with extended parameters
void DrawTextureEx(Texture2D texture, Vector2 position, float rotation, float scale, Color tint)
{
glEnable(GL_TEXTURE_2D); // Enable textures usage
glBindTexture(GL_TEXTURE_2D, texture.glId);
glPushMatrix();
// NOTE: Rotation is applied before translation and scaling, even being called in inverse order...
// NOTE: Rotation point is upper-left corner
glTranslatef(position.x, position.y, 0);
glScalef(scale, scale, 1.0f);
glRotatef(rotation, 0, 0, 1);
glBegin(GL_QUADS);
glColor4ub(tint.r, tint.g, tint.b, tint.a);
glNormal3f(0.0f, 0.0f, 1.0f); // Normal vector pointing towards viewer
glTexCoord2f(0.0f, 0.0f); glVertex2f(0.0f, 0.0f); // Bottom-left corner for texture and quad
glTexCoord2f(1.0f, 0.0f); glVertex2f(texture.width, 0.0f); // Bottom-right corner for texture and quad
glTexCoord2f(1.0f, 1.0f); glVertex2f(texture.width, texture.height); // Top-right corner for texture and quad
glTexCoord2f(0.0f, 1.0f); glVertex2f(0.0f, texture.height); // Top-left corner for texture and quad
glEnd();
glPopMatrix();
glDisable(GL_TEXTURE_2D); // Disable textures usage
}
// Draw a part of a texture (defined by a rectangle)
void DrawTextureRec(Texture2D texture, Rectangle sourceRec, Vector2 position, float scale, Color tint)
{
glEnable(GL_TEXTURE_2D); // Enable textures usage
glBindTexture(GL_TEXTURE_2D, texture.glId);
glPushMatrix();
glTranslatef(position.x, position.y, 0);
glScalef(scale, scale, 1.0f);
//glRotatef(rotation, 0, 0, 1);
glBegin(GL_QUADS);
glColor4ub(tint.r, tint.g, tint.b, tint.a);
glNormal3f(0.0f, 0.0f, 1.0f); // Normal vector pointing towards viewer
// Bottom-left corner for texture and quad
glTexCoord2f((float)sourceRec.x / texture.width, (float)sourceRec.y / texture.height);
glVertex2f(0.0f, 0.0f);
// Bottom-right corner for texture and quad
glTexCoord2f((float)(sourceRec.x + sourceRec.width) / texture.width, (float)sourceRec.y / texture.height);
glVertex2f(sourceRec.width, 0.0f);
// Top-right corner for texture and quad
glTexCoord2f((float)(sourceRec.x + sourceRec.width) / texture.width, (float)(sourceRec.y + sourceRec.height) / texture.height);
glVertex2f(sourceRec.width, sourceRec.height);
// Top-left corner for texture and quad
glTexCoord2f((float)sourceRec.x / texture.width, (float)(sourceRec.y + sourceRec.height) / texture.height);
glVertex2f(0.0f, sourceRec.height);
glEnd();
glPopMatrix();
glDisable(GL_TEXTURE_2D); // Disable textures usage
}
// Creates a bitmap (BMP) file from an array of pixel data
// NOTE: This function is only used by module [core], not explicitly available to raylib users
extern void WriteBitmap(const char *fileName, const Color *imgDataPixel, int width, int height)
{
int filesize = 54 + 3*width*height;
unsigned char bmpFileHeader[14] = {'B','M', 0,0,0,0, 0,0, 0,0, 54,0,0,0}; // Standard BMP file header
unsigned char bmpInfoHeader[40] = {40,0,0,0, 0,0,0,0, 0,0,0,0, 1,0, 24,0}; // Standard BMP info header
bmpFileHeader[2] = (unsigned char)(filesize);
bmpFileHeader[3] = (unsigned char)(filesize>>8);
bmpFileHeader[4] = (unsigned char)(filesize>>16);
bmpFileHeader[5] = (unsigned char)(filesize>>24);
bmpInfoHeader[4] = (unsigned char)(width);
bmpInfoHeader[5] = (unsigned char)(width>>8);
bmpInfoHeader[6] = (unsigned char)(width>>16);
bmpInfoHeader[7] = (unsigned char)(width>>24);
bmpInfoHeader[8] = (unsigned char)(height);
bmpInfoHeader[9] = (unsigned char)(height>>8);
bmpInfoHeader[10] = (unsigned char)(height>>16);
bmpInfoHeader[11] = (unsigned char)(height>>24);
FILE *bmpFile = fopen(fileName, "wb"); // Define a pointer to bitmap file and open it in write-binary mode
// NOTE: fwrite parameters are: data pointer, size in bytes of each element to be written, number of elements, file-to-write pointer
fwrite(bmpFileHeader, sizeof(unsigned char), 14, bmpFile); // Write BMP file header data
fwrite(bmpInfoHeader, sizeof(unsigned char), 40, bmpFile); // Write BMP info header data
// Write pixel data to file
for (int y = 0; y < height ; y++)
{
for (int x = 0; x < width; x++)
{
fputc(imgDataPixel[x + y*width].b, bmpFile);
fputc(imgDataPixel[x + y*width].g, bmpFile);
fputc(imgDataPixel[x + y*width].r, bmpFile);
}
}
fclose(bmpFile); // Close bitmap file
}