SDL_Texture works for SDL_RenderGeometry() in SDL2 but not for SDL3!? #11554

stalbordboat · 2024-11-29T11:53:19Z

I've been trying to migrate from SDL2 to SDL3 and ran into a rode block when using the SDL_RenderGeometry() function. I'm not sure if this is a bug or something that I'm just simply missing, so I thought I'd ask it here. When I try to render a triangle with a texture in SDL2 it works like a charm, but when I do the equivalent in SDL3 all I get is a white triangle. I'm using the same bmp image. The only discernible difference between the two, from what I can see is that SDL3's SDL_Vertex uses SDL_FColor instead of SDL_Color. Here is my working SDL2 code:

#include <SDL.h>

static SDL_Window   *window   = NULL;
static SDL_Renderer *renderer = NULL;

static SDL_bool is_running = SDL_TRUE;

static SDL_Event event = {0};

static SDL_Vertex vertex_1 = {{100.5, 100.5}, {255, 255, 255, 255}, {1, 1}};
static SDL_Vertex vertex_2 = {{200.5, 100.5}, {255, 255, 255, 255}, {1, 1}};
static SDL_Vertex vertex_3 = {{100.5, 200.5}, {255, 255, 255, 255}, {1, 1}};

static SDL_Vertex vertices[3] = {0};

static SDL_Surface *surface = NULL;
static SDL_Texture *texture = NULL;

int main(void) {
        int flags = SDL_RENDERER_ACCELERATED|SDL_RENDERER_PRESENTVSYNC;
        vertices[0] = vertex_1;
        vertices[1] = vertex_2;
        vertices[2] = vertex_3;

        SDL_Init(SDL_INIT_VIDEO);

        window   = SDL_CreateWindow("", 0, 0, 1280, 720, SDL_WINDOW_SHOWN);
        renderer = SDL_CreateRenderer(window, -1, flags);

        surface = SDL_LoadBMP("Icon.bmp");
        texture = SDL_CreateTextureFromSurface(renderer, surface);

        while(is_running) {
                SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);

                SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);

                SDL_RenderClear(renderer);

                while(SDL_PollEvent(&event)) {
                        switch(event.type) {
                                case SDL_QUIT:
                                        is_running = SDL_FALSE;
                                        break;
                        }
                }

                vertices[0].color.a -= 10;
                vertices[1].color.a -= 10;
                vertices[2].color.a -= 10;
                SDL_RenderGeometry(renderer, texture, vertices, 3, NULL, 0);

                SDL_RenderPresent(renderer);
        }

        SDL_FreeSurface(surface);
        SDL_DestroyTexture(texture);
        SDL_DestroyRenderer(renderer);
        SDL_DestroyWindow(window);
        SDL_Quit();
}

This produces the texture mapped triangle and flashes it as I expected.

and here's the equvelent SDL3 code:

#include <SDL3/SDL.h>

static SDL_Window   *window   = NULL;
static SDL_Renderer *renderer = NULL;

static bool is_running = true;

static SDL_Event event = {0};

static SDL_Vertex vertex_1 = {{100.5, 100.5}, {255, 255, 255, 255}, {1, 1}};
static SDL_Vertex vertex_2 = {{200.5, 100.5}, {255, 255, 255, 255}, {1, 1}};
static SDL_Vertex vertex_3 = {{100.5, 200.5}, {255, 255, 255, 255}, {1, 1}};

static SDL_Vertex vertices[3] = {0};

static SDL_Surface *surface = NULL;
static SDL_Texture *texture = NULL;

int main(void) {
        vertices[0] = vertex_1;
        vertices[1] = vertex_2;
        vertices[2] = vertex_3;

        SDL_Init(SDL_INIT_VIDEO);

        window   = SDL_CreateWindow("", 1280, 720, 0);
        renderer = SDL_CreateRenderer(window, NULL);
        SDL_SetRenderVSync(renderer, 1);

        surface = SDL_LoadBMP("Icon.bmp");
        texture = SDL_CreateTextureFromSurface(renderer, surface);

        while(is_running) {
                SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);

                SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);

                SDL_RenderClear(renderer);

                while(SDL_PollEvent(&event)) {
                        switch(event.type) {
                                case SDL_EVENT_QUIT:
                                        is_running = false;
                                        break;
                        }
                }

                vertices[0].color.a -= 10;
                vertices[1].color.a -= 10;
                vertices[2].color.a -= 10;
                SDL_RenderGeometry(renderer, texture, vertices, 3, NULL, 0);

                SDL_RenderPresent(renderer);
        }

        SDL_DestroySurface(surface);
        SDL_DestroyTexture(texture);
        SDL_DestroyRenderer(renderer);
        SDL_DestroyWindow(window);
        SDL_Quit();
}

This is does not seem to produce the texture mapping at all, and when I log it to see if the texture is NULL, it is not NULL!

Lastly, this is the texture that I'm loading in both example.

madebr · 2024-11-29T12:01:34Z

SDL3's SDL_Vertex.color has float members with a range 0.f-1.f

stalbordboat closed this as completed Nov 30, 2024

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SDL_Texture works for SDL_RenderGeometry() in SDL2 but not for SDL3!? #11554

SDL_Texture works for SDL_RenderGeometry() in SDL2 but not for SDL3!? #11554

SDL_Texture works for SDL_RenderGeometry() in SDL2 but not for SDL3!? #11554

SDL_Texture works for SDL_RenderGeometry() in SDL2 but not for SDL3!? #11554

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