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Size: 4268
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Size: 4458
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| Deletions are marked like this. | Additions are marked like this. |
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/*For loop counters*/ int i; int n; /*Rects for drawing. Probably overkill, but defining too much is certainly better than errors from uninitilization*/ |
/* Rectangles for drawing which will specify source (inside the texture) and target (on the screen) for rendering our textures. */ |
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| /*The creation of all the necessary stuff*/ Main_Window = SDL_CreateWindow("SDL_RenderCopy Example", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 580, SDL_WINDOW_SHOWN); |
/* Before we can render anything, we need a window and a renderer */ Main_Window = SDL_CreateWindow("SDL_RenderCopy Example", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 580, SDL_WINDOW_SHOWN); |
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/*The loading of the background texture. I think using CreateTextureFromSurface is the best way to do this without using SDL_image. My background of choice is a calming field picture*/ |
/* The loading of the background texture. Since SDL_LoadBMP returns a surface, we convert it to a texture afterwards for fast accelerated blitting. */ |
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| SDL_FreeSurface(Loading_Surf); // we got the texture now -> free surface | |
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/*Clear the loading surface, load a new one, and creating the second texture. This one has a 2x2 grid of blue shapes on a black background.*/ Loading_Surf = NULL; |
/* Load an additional texture */ |
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| SDL_FreeSurface(Loading_Surf); //always good to free stuff as soon as you're done with it | SDL_FreeSurface(Loading_Surf); |
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/*now onto the fun part. This will render a rotating selection of the blue shapes in the middle of the screen*/ |
/* now onto the fun part. This will render a rotating selection of the blue shapes in the middle of the screen */ int i; int n; |
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| SDL_RenderCopy (Main_Renderer,Background_Tx,NULL,NULL); SDL_RenderCopy (Main_Renderer,BlueShapes,&SrcR,&DestR); |
/* render background, whereas NULL for source and destination rectangles just means "use the default" */ SDL_RenderCopy(Main_Renderer, Background_Tx, NULL, NULL); /* render the current animation step of our shape */ SDL_RenderCopy(Main_Renderer, BlueShapes, &SrcR, &DestR); |
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| /* in my mind, I think of the renderer as a big canvis, and when you RenderCopy you are adding paint on it, each time adding it over top. You can change how it blends with the stuff that the new data goes over. If you're stuck on the whole renderer idea, coming from 1.2 surfaces and bliting, think of the renderer as your main surface, and RenderCopy as the blit function to that main surface, with RenderPresent as the old flip function.*/ | /* The renderer works pretty much like a big canvas: when you RenderCopy you are adding paint, each time adding it on top. You can change how it blends with the stuff that the new data goes over. When your 'picture' is complete, you show it by using SDL_RenderPresent. */ |
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| /* SDL 1.2 hint: If you're stuck on the whole renderer idea coming from 1.2 surfaces and blitting, think of the renderer as your main surface, and SDL_RenderCopy as the blit function to that main surface, with SDL_RenderPresent as the old SDL_Flip function.*/ |
SDL_RenderCopy
Use this function to copy a portion of the texture to the current rendering target.
Contents
Syntax
int SDL_RenderCopy(SDL_Renderer* renderer,
SDL_Texture* texture,
const SDL_Rect* srcrect,
const SDL_Rect* dstrect)
Function Parameters
renderer |
the rendering context |
texture |
the source texture; see Remarks for details |
srcrect |
the source SDL_Rect structure or NULL for the entire texture |
dstrect |
the destination SDL_Rect structure or NULL for the entire rendering target. The texture will be stretched to fill the given rectangle. |
Return Value
Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.
Code Examples
#include <SDL/SDL.h>
#define SHAPE_SIZE 16
int main()
{
SDL_Window* Main_Window;
SDL_Renderer* Main_Renderer;
SDL_Surface* Loading_Surf;
SDL_Texture* Background_Tx;
SDL_Texture* BlueShapes;
/* Rectangles for drawing which will specify source (inside the texture)
and target (on the screen) for rendering our textures. */
SDL_Rect SrcR;
SDL_Rect DestR;
SrcR.x = 0;
SrcR.y = 0;
SrcR.w = SHAPE_SIZE;
SrcR.h = SHAPE_SIZE;
DestR.x = 640 / 2 - SHAPE_SIZE / 2;
DestR.y = 580 / 2 - SHAPE_SIZE / 2;
DestR.w = SHAPE_SIZE;
DestR.h = SHAPE_SIZE;
/* Before we can render anything, we need a window and a renderer */
Main_Window = SDL_CreateWindow("SDL_RenderCopy Example",
SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 580, SDL_WINDOW_SHOWN);
Main_Renderer = SDL_CreateRenderer(Main_Window, -1, SDL_RENDERER_ACCELERATED);
/* The loading of the background texture. Since SDL_LoadBMP returns
a surface, we convert it to a texture afterwards for fast accelerated
blitting. */
Loading_Surf = SDL_LoadBMP("Background.bmp");
Background_Tx = SDL_CreateTextureFromSurface(Main_Renderer, Loading_Surf);
SDL_FreeSurface(Loading_Surf); // we got the texture now -> free surface
/* Load an additional texture */
Loading_Surf = SDL_LoadBMP("Blueshapes.bmp");
BlueShapes = SDL_CreateTextureFromSurface(Main_Renderer, Loading_Surf);
SDL_FreeSurface(Loading_Surf);
/* now onto the fun part.
This will render a rotating selection of the blue shapes
in the middle of the screen */
int i;
int n;
for(i=0;i<2;i++)
{
for(n=0;n<4;n++)
{
SrcR.x = SHAPE_SIZE * (n % 2);
if(n > 1)
{
SrcR.y = SHAPE_SIZE;
}
else
{
SrcR.y = 0;
}
/* render background, whereas NULL for source and destination
rectangles just means "use the default" */
SDL_RenderCopy(Main_Renderer, Background_Tx, NULL, NULL);
/* render the current animation step of our shape */
SDL_RenderCopy(Main_Renderer, BlueShapes, &SrcR, &DestR);
SDL_RenderPresent(Main_Renderer);
SDL_Delay(500);
}
}
/* The renderer works pretty much like a big canvas:
when you RenderCopy you are adding paint, each time adding it
on top.
You can change how it blends with the stuff that
the new data goes over.
When your 'picture' is complete, you show it
by using SDL_RenderPresent. */
/* SDL 1.2 hint: If you're stuck on the whole renderer idea coming
from 1.2 surfaces and blitting, think of the renderer as your
main surface, and SDL_RenderCopy as the blit function to that main
surface, with SDL_RenderPresent as the old SDL_Flip function.*/
SDL_DestroyTexture(BlueShapes);
SDL_DestroyTexture(Background_Tx);
SDL_DestroyRenderer(Main_Renderer);
SDL_DestroyWindow(Main_Window);
SDL_Quit();
return 1;
}
Remarks
The texture is blended with the destination based on its blend mode set with SDL_SetTextureBlendMode().
The texture color is affected based on its color modulation set by SDL_SetTextureColorMod().
The texture alpha is affected based on its alpha modulation set by SDL_SetTextureAlphaMod().
Related Functions
