Print Page - How to draw VertexArray ?

Title: How to draw VertexArray ?
Post by: Takoo on December 26, 2017, 12:42:13 am

Hello,
My goal is to draw a tylemap from int*.
After 2 hours of research i didn't resolve my problem :

[Takoo@localhost my_runner_2017]$ make re
rm -f ./src/main.o
rm -f my_runner
gcc -g3 -Wextra -Wall -Werror -I./include   -c -o src/main.o src/main.c
src/main.c: In function ‘main’:
src/main.c:60:50: error: incompatible type for argument 3 of ‘sfRenderWindow_drawVertexArray’
   sfRenderWindow_drawVertexArray(window, vertex, states);
                                                  ^~~~~~
In file included from /usr/local/include/SFML/Graphics.h:46:0,
                 from src/../include/my.h:11,
                 from src/main.c:8:
/usr/local/include/SFML/Graphics/RenderWindow.h:432:25: note: expected ‘const sfRenderStates * {aka const struct <anonymous> *}’ but argument is of type ‘sfRenderStates {aka struct <anonymous>}’
 CSFML_GRAPHICS_API void sfRenderWindow_drawVertexArray(sfRenderWindow* renderWindow, const sfVertexArray* object, const sfRenderStates* states);
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
make: *** [<builtin>: src/main.o] Error 1
[Takoo@localhost my_runner_2017]$ 
 

I don't understand why my sfRenderWindow_drawVertexArray (L.60) wait a * sfRenderStates while every examples on web uses sfRenderStates without "*".

Here is my code :

(click to show/hide)

#include "../include/my.h"

int main()
{
        int width = 5;
        int height = 3;
        sfVideoMode mode = {512, 256, 32};
        sfRenderWindow *window = sfRenderWindow_create(mode, "MY_RUNNER", sfResize | sfClose, NULL);
        int lvl[] =
        {
                2, 2, 2, 2, 2,
                2, 2, 1, 2, 1,
                0, 0, 0, 0, 0,
        };
        sfTexture *texture = sfTexture_createFromFile("./img/social.png", NULL);
        sfVertexArray *vertex = sfVertexArray_create();
        sfVertexArray_setPrimitiveType(vertex, sfQuads);
        sfVertexArray_resize(vertex, width * height * 4);
        for (int i = 0; i < width; i++) {
                for (int j = 0; j < height; j++) {
                        int nbr = lvl[i + j * width];
                        sfVertex *quad = sfVertexArray_getVertex(vertex, (i + j * width) * 4);
                        quad[0].position = (sfVector2f){i * 32, j * 32};
                        quad[1].position = (sfVector2f){(i + 1) * 32, j * 32};
                        quad[2].position = (sfVector2f){(i + 1) * 32, (j + 1) * 32};
                        quad[3].position = (sfVector2f){i * 32, (j + 1) * 32};
                        
                        quad[0].texCoords = (sfVector2f){nbr * 32, 0};
                        quad[1].texCoords = (sfVector2f){(nbr + 1) * 32, 0};
                        quad[2].texCoords = (sfVector2f){(nbr + 1) * 32, 32};
                        quad[3].texCoords = (sfVector2f){nbr * 32, 32};
                }
        }
        sfRenderStates states;
        states.texture = texture;
        
        
        
        while (sfRenderWindow_isOpen(window))
        {
                sfEvent event;
                while (sfRenderWindow_pollEvent(window, &event))
                {
                        if (event.type == sfEvtClosed)
                                sfRenderWindow_close(window);
                }
                sfRenderWindow_clear(window, sfBlack);
                sfRenderWindow_drawVertexArray(window, vertex, states);
                sfRenderWindow_display(window);
        }
        sfTexture_destroy(texture);
        sfVertexArray_destroy(vertex);
        sfRenderWindow_destroy(window);
        return (0);
}
 

Thank's for ur help ! :(

Title: Re: How to draw VertexArray ?
Post by: FRex on December 26, 2017, 01:58:56 am

Most examples online are in C++ and not C. The error is clear, you need to pass a pointer to render states to that function.

Title: Re: How to draw VertexArray ?
Post by: Takoo on December 26, 2017, 02:24:04 pm

Quote from: FRex on December 26, 2017, 01:58:56 am

Most examples online are in C++ and not C. The error is clear, you need to pass a pointer to render states to that function.

Hi, thanks for ur reply.
I found the problem but now my program segfault when I set texture to my RenderState (L.42: states->texture = texture;).
Error :

(click to show/hide)

My code :

(click to show/hide)

#include "../include/my.h"

int main()
{
        int width = 5;
        int height = 3;
        sfVideoMode mode = {160, 96, 32};
        sfRenderWindow *window = sfRenderWindow_create(mode, "MY_RUNNER", sfResize | sfClose, NULL);
        int lvl[] =
        {
                2, 2, 2, 2, 2,
                2, 2, 1, 2, 1,
                0, 0, 0, 0, 0,
        };
        sfTexture *texture = sfTexture_createFromFile("img/bg0.jpg", NULL);
        sfVertexArray *vertex = sfVertexArray_create();
        sfVertexArray_setPrimitiveType(vertex, sfQuads);
        sfVertexArray_resize(vertex, width * height * 4);
        for (int i = 0; i < width; i++) {
                for (int j = 0; j < height; j++) {
                        int nbr = lvl[i + j * width];
                        sfVertex *quad = sfVertexArray_getVertex(vertex, (i + j * width) * 4);
                        quad[0].position = (sfVector2f){i * 32, j * 32};
                        quad[1].position = (sfVector2f){(i + 1) * 32, j * 32};
                        quad[2].position = (sfVector2f){(i + 1) * 32, (j + 1) * 32};
                        quad[3].position = (sfVector2f){i * 32, (j + 1) * 32};
                        
                        quad[0].texCoords = (sfVector2f){nbr * 32, 0};
                        quad[1].texCoords = (sfVector2f){(nbr + 1) * 32, 0};
                        quad[2].texCoords = (sfVector2f){(nbr + 1) * 32, 32};
                        quad[3].texCoords = (sfVector2f){nbr * 32, 32};
                }
        }
        sfRenderStates *states = NULL;
        states->texture = texture;  << SEGFAULT HERE <<
        
        
        while (sfRenderWindow_isOpen(window))
        {
                sfEvent event;
                while (sfRenderWindow_pollEvent(window, &event))
                {
                        if (event.type == sfEvtClosed)
                                sfRenderWindow_close(window);
                }
                sfRenderWindow_clear(window, sfBlack);
                sfRenderWindow_drawVertexArray(window, vertex, states);
                sfRenderWindow_display(window);
        }
        sfTexture_destroy(texture);
        sfVertexArray_destroy(vertex);
        sfRenderWindow_destroy(window);
        return (0);
}
 

Title: Re: How to draw VertexArray ?
Post by: Laurent on December 26, 2017, 07:20:05 pm

states is NULL, you can't access its texture member. You need a valid sfRenderStates instance.

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Help => General => Topic started by: Takoo on December 26, 2017, 12:42:13 am